In all the three lakes 148 species of phytoplankton and 79 species of zooplankton have been recorded. A list of all the species encountered during present investigation, along with their presence/absence, frequency of appearance, abundance and seasonality has been given. Higher values of Shannon-Wiener index (3.187-3.310), Simpson index (0.942-0.948) and Margalef index (4.959-5.388) were observed in Prashar Lake, whereas lower values of Shannon-Wiener Index (1.177-1.924), Simpson index (0.153-0.513) and Margalef index (1.398-1.650) were recorded in Rewalsar Lake. Higher values (0.432-0.860) of Berger-Parker index was observed in Rewalsar Lake and lower value (0.110-0.117) in Prashar Lake. Higher values in Prashar Lake indicate healthy status of the lake and lower values in Rewalsar Lake showed unhealthy and polluted status of the lake. Based on the trophic classification of waters given by the Vollenweider (1968) and Rodhe (1969) on the basis of productivity, Nygaard’s trophic state indices, productivity values and richness of nutrients, Rewalsar and Kuntbhyog lakes could be categorised as eutrophic, whereas Prashar Lake as oligo-eutorphic.