Shellfish cultivation in Republic of Croatia emphasizes the importance of popularizing world problem of shellfish harvesting, but also possible solutions through aquaculture production and the importance of constant control of the shellfish farms due to a variety of health problems that contaminated shellfish organisms can cause. The aim of this study was to show the cultivation of mussels in the Adriatic Sea. The introductory chapter describes the process of cultivation, gives additional information about active farms and important factors for the production of shellfish. The production data tends to show the real situation of shellfish cultivation in Republic of Croatia. Further described are diseases that affect shellfish and potential hazards that may occur by eating contaminated shellfish. The final part is focused on the legislation of the Republic of Croatian, which includes a variety of policies and plans for monitoring the cultivation of shellfish. Although the course of history has shown many attempts of shellfish farming in various locations which have experienced a series of failures in the effort and desire to develop competitive shellfish cultivation in Republic of Croatia, many of these places still have great production, export, tourism and development prospects of successful shellfish farming in the future.