This paper presents the latest data on the Mesolithic settlements in the Baltic Seacoast area of Lithuania. For thousands of years changing natural conditions and thedevelopment of the Baltic Sea have led to the fact that there are currently only a fewMesolithic sites known in this region. Their material mainly consists of stray finds,however there are some findings wich were found during systematical field surveysand excavations. The underwater archaeological research, alongside with alreadyfound relict coasts of the Baltic Sea and flooded ancient pine forest suggests thatmost of the Mesolithic period settlements should be submerged and nowadays canbe found at the bed of the sea. The team of archeologists, bioarcheologists and geologistsat the University of Klaipėda has launched a scientific project, which will seekto find flooded and existing Mesolithic settlements in the sea bed and in presentcoastland area of Lithuania.