The Adriatic Sea is a part of the eastern Mediterranean Sea. A few species of dolphins are occasionally seen in the Adriatic Sea, but the only abundant population of dolphins is the Kvarnerić bottlenose dolphin population. That is also the only resident population of marine mammals in this sea. Human activity affects dolphins directly and indirectly by habitat degradation, reduction of food prey, disturbance and cause of injuries or death. The main threats in recent times include overfishing, incidental mortality in fishing gear, toxic substances and tourism. Because of that, the Adriatic bottlenose dolphin meta-population has a decreasing trend and is listed as endangered species, while the short-beaked common dolphin, once abundant, is listed as probably endangered. The dolphins in the Adriatic Sea are legally protected under the Croatian law and international regulations. It is also planned to establish a regional park around the islands of Lošinj and Cres. They have been studied on a number of locations, and in Croatia the research is carried out by the Blue World Institute, the Faculty of Veterinary Medicine of University of Zagreb and the CROdolphin database. Still, more research should be done and the on-going should be improved.