In the the doctoral dissertation titled "Influence of the perception of security on the development of entrepreneurship in tourism" tourism safety from a theoretical and practical perspective is explored. Along with the theoretical knowledge dealing with the negative effects of security problems and their impact on the destination tourism development as well as the practical knowledge dealing with the same issue, the author tries to establish the link between tourism safety and entrepreneurship development, i.e. in which way the entrepreneurial activities in a tourist destination are affected by the perception of tourism safety. The research is based on the fact that the negative implications of security affect all stakeholders in a tourist destination, and especially entrepreneurs in tourism, whose business performance depends on the number of visitor arrivals at a destination. When considering the issue of security in the context of tourism in the 21st century, various forms of security threats are emerging, such as life and health threats, environmental disasters and environmental pollution threats, threats caused by various criminal offenses such as criminal offenses against personal dignity and morals, criminal acts against life etc., as well as threats caused by terrorist attacks, regional wars, threats as a result of human trafficking, endangering the material assets of tourists and of tourist service providers, and also the cultural monuments in a tourist destination. Various other threats, such as earthquakes and other natural disasters can also be added. The effects of security levels in a tourist destination can be perceived through the quantitative indicators of realized tourist arrivals and overnight stays in the destination, which implicitly affects the business of the tourist offer providers in the destination and the development of the entrepreneurship in the destination. Therefore, the understanding of tourism security is essential for the development of entrepreneurship in a tourist destination. The author updates the security in the context of the realization of tourism turnover in the destination, whereby the current global and regional impacts, such as terrorism and wars, as well as their impact on entrepreneurs in the tourist destination itself are anlysed. The research results point to the relationship between tourism and security, in particular to the relationship between the entrepreneurship in tourism and security. Terrorist attacks in the United States, France, Spain, the United Kingdom, Turkey and the Mediterranean countries, the economic crisis, human health threats as a result of epidemics of contagious diseases and others have reduced the tourist motivation to travel, and on the other hand European tourists have shown a greater motivation to travel to destinations closer to their permanent residence and to avoid distant destinations. The economic crisis is causing a decline in the standard of living, which demotivates potential tourists to undertake travel tours, especially those that require greater spending. Tourists get more oriented towards tourist trips within the national borders and towards more affordable accommodation facilities. In response to the economic crisis that started in late 2007, and which exerted the negative consequences for tourism in 2008 and 2009, the hotels offered lower accommodation prices. Although the decline of the capacity utilization rate was obvious, it was lower than it would be with the same prices as before the start of the economic crisis. The terrorist attack in New York has been strongly reflected in tourism, and the destinations mostly accessed by airplanes were strongly affected by the decline in tourist turnover and tourism revenue. On the other hand, the growth of tourist turnover was registered in countries that are not affected by various security problems. Therefore, for the development of tourism in a country, and thus for tourism entrepreneurship, the establishment of an efficient security system is of utmost importance. The goal is to create an environment where tourists will be safe. This can be achieved by various security measures in tourism, which may be implemented as prevention or as a response following a certain security situation or a security incident. At the global level, however, the trend in tourism flows suggests that security in tourism has no significant impact on tourism trends. Despite a variety of security threats at the regional and local level, and consequently the total absence of tourist travel in these areas, global travel trends show a growing trend on a global scale. Tourist trips are therefore being displaced from destinations that are insecure to destinations that show a certain level of security for tourists. Protection and security in tourism are, therefore, complex multidimensional terms that encompass a large number of components including: political security, public safety, health and sanitary security, personal data protection, legal protection of tourists, consumers' protection, communication security, obtaining authentic data, quality assurance services etc. The author's research results move the boundaries in terms of safety issue being considered as an element of tourism offer and in terms of its importance for tourism development and entrepreneurship in tourism. Data on safety level and the impact measurement on business performance of entrepreneurs make it possible to highlight security as a competitive edge of the Republic of Croatia on the tourist market. They also make it possible to timely response to the reduction of the level of security and to adequately manage security risks in tourism. The analysis of entrepreneurship development in tourism in the Republic of Croatia has clearly indicated the negative effects of wars on entrepreneurial activities. Only after the end of war operations the recovery and growth of entrepreneurship in tourism appears. Creating an image of a safe destination in the awareness of tourists was one of the priorities for returning to the tourism market and achieving competitiveness. Although creating the image of a safe destination was not an easy process, the Republic of Croatia has positioned itself as a safe destination on the European and world tourism market for the next period. This is certainly contributed through the different measures of protection and security of tourists, which are carried out both on the macro-level and at the level of individual tourist destinations and at the level of accommodation and other catering facilities. Referring to the fact that entrepreneurship is closely connected to social, economic and political events in the tourist destination area, which is supported by data on the number of companies in the Republic of Croatia during the war and their growth at the end of the war and the creation of conditions for safe arrival of tourists, the link between entrepreneurship in tourism and security has been identified. This is also evident in the years characterized by the economic crisis. Tourism sensitivity to economic changes can easily be recognized through the reduction of tourism activities on global scale. With the reduction of tourism activities, the decline in expenditure of domestic guests in catering facilities causes negative business results for entrepreneurs, and closing of catering facilities, especially small businesses. One of the limiting factors of achieving a higher level of security in a tourist destination is, of course, the unfavorable structure of the accommodation facilities, where hotels as facilities of the highest level of security for tourists participate with a very small share, so that it is justified to raise the question on how much the structure of the accommodation supply of the Republic of Croatia can satisfy the needs of the Croatian tourism. In line with the security situation at a global level, security is based on the strategic features of Croatian tourism. The author has performed the research on the guests' satisfaction regarding their personal security in a tourist facility, the safety of the traffic infrastructure, the safety of the beaches and the security in the tourist destination which has confirmed that the guests visiting Croatia are satisfied with certain elements of safety and their greatest satisfaction is attributed to the accommodation facility. The implementation of security standards in catering facilities also indicates the significance of safety. The satisfaction of guests with a security aspect in tourism in the Republic of Croatia confirms the image of Croatia as a safe tourist destination. In the area of security, Croatia is competitive on the tourist market. This has certainly been supported through the measures taken at the level of a particular tourist destination in which all the stakeholders participate. According to the research results performed by the author, only a small number of guests have complaints about security, and security complaints mainly concern food poisoning and inadequate security measures in facilities. When deciding on a destination, the most important factors for guests are climate conditions, while health problems are the most frequent problems the guests are concerned about upon their arrival to a destination. When the guests try to remember Croatia, it is primarily the image of Croatia as 'the beautiful coast, the sea, the islands'. The satisfaction with the security provided by entrepreneurs in their accommodation and other facilities, as well as by the stakeholders in the destination builds a prerequisite for achieving competitiveness on the tourist market at a time when safety builds an important aspect of the tourist development of the destination. When exploring security from the aspect of tourism and entrepreneurship, the so-called „tourism criminality“ is being investigated because it has a significant impact on the tourists' negative perception of their security in a particular destination. The investigation of secondary data on misdemeanors and criminal offenses in the Republic of Croatia showed a positive correlation between criminality and the number of tourist arrivals and overnight stays. With the growth of tourism in the Republic of Croatia, the criminality rate is also growing. A positive correlation has also been observed by analyzing traffic accidents and the number of traffic participants. Despite significant gains in increasing traffic safety, it can still be considered as unsatisfactory. One of the tasks of the Republic of Croatia is to respond to expectations regarding the safety of all traffic participants, as well as the tourists by satisfying the highest standards of safety and protection in all forms of traffic. This necessitates the redirection of road traffic participants to rail transport, which requires significant activities to improve the quality of the rail infrastructure and superstructure in line with the trends in the transport services market. This paper is based on the scientific knowledge and practical knowledge focused on the importance of the safety element in tourism trends. It demonstrates the impact of security on the development of entrepreneurship in tourism and proposes a security system that will enable the creation of an environment suitable for undisturbed development of entrepreneurship in tourism. The set objectives of the thesis related to the critical analysis of the impact of security on tourism trends at the global level, the study of the security level in tourism in the Republic of Croatia, its impact on Croatian tourism and on entrepreneurship in Croatian tourism, analysis of tourist attitudes regarding the safety of tourism in the Republic of Croatia as well as safety as an element of the Croatian tourism supply, a comparative analysis of security in Croatian tourist destinations and competitive countries provide guidelines for establishing an adequate security system both at the tourist destination level and at the level of an individual tourist facility, whereby the security level in tourism in the Republic of Croatia could be increased and consequently the business results of entrepreneurs in tourism could be improved.