The seven lakes of San Pablo City, Laguna are rich in malacofaunal diversity. Around 17 species of mollusks (15 gastropods and 2 bivalves) were identified with Stenothyra sp. as the most abundant. Three invasive species, Pomacea canaliculata, Sinotaia quadrata, and Sinanodonta woodiana were recorded. Species richness was highest in Lake Sampaloc (n=17) while diversity and evenness was highest in Lake Bunot (H’= 2.10, J’=0.54). These mollusks, although still abundant, are threatened by increasing water salinity, total dissolved solids, and temperature, and decreasing DO due to rapid urban development.