Entrepreneurial projects and start-up initiatives are an important factor for the progress of every economy. Lately, their importance has been significantly increased. As a result, governments around the world have changed their regulation and created incentives to encourage development of start-up projects. However, the statistics show that start-up projects have an extremely high failure rate. It can be speculated that this is a consequence of a lack of strategic planning, wrong marketing investments or inefficient resource allocation. In order to minimize the failure rate of some start-up projects, the specific reasons for start-up failures need to be researched with the scope of avoiding them. This research seeks to discover the reasons and factors of success and failure of start-ups, to determine whether there are assumptions and patterns that lead to failure and/or success of start-ups, as well as to identify the factors that can help a start-up on the road to success. After the examination of the available literature and after checking the previous research, the empirical research has been made by using the questionnaire for young people as examinees – the potential start-upers, as well as the interview method for interviewing relevant experts and connoisseurs of the Croatian start-up scene. The results of both surveys were converted into various recommendations for enabling successful activation and management of start-up ventures in Croatia.