The 2002 field research on the malacofauna of selected watercourses and reservoirs in Vilnius (Lithuania) revealed the occurrence of 35 mollusc species represented by 1,915 live specimens. Out of the 50 water mollusc species recorded from the Vilnius region before World War II, 30 were represented by live specimens in this study. Five of the live species found in 2002 had not been earlier recorded from the area. The highest number of species represented by live specimens was found in the river Vilnia (23) and in its reservoir (22). Fewer species were found in the river Viliya (15) and in the reservoir on the stream Cedronas (4). No live molluscs were collected in the stream Cedronas.