This paper presents an investment project through estimation of the need for construction of congress center in Zagreb. The purpose of this bachelor thesis is assessment of positive impact on the city and its inhabitants that the congress center would yield. This paper analyzes historical data, future forecasts of key indicators – tourist turnover and their preferences - as well as destination and location. Furthermore, the aim is to propose an improvement for Zagreb's congress tourism supply. In order to thoroughly examine the market, in-depth analysis of market and competition, benchmarking analysis, and a questionnaire have been undertaken. The majority of data for the seminar paper have been collected by the author through market research. The survey has been conducted on the sample of employees in the tourism sector by e-mail correspondence. The results indicated that a large number of survey sample acknowledged desire for a construction of congress center. According to the data on tourist turnover in Croatia and Zagreb, arrivals and overnight stays in Croatia and Zagreb increased compared to the previous period with increasing demand for congressional content. With construction of new airport in Zagreb, one of the pre-requirements for the growth of tourism in the destination has been accomplished.