Abstract: The present study deals with the evaluation of phytoplankton community of Nigeen lake which is one of the rare aquatic ecosystem wherein the human population live inside the lake in house boats which serves also an attraction for high end tourism. Having this feature under consideration and also lack of proper sewage system connectivity of the house boats, it was thought worthwhile to have a pilot assessment of phytoplankton community in the lake. During the study period, a total of 65 phytoplankton taxa were identified representing four classes namely Chlorophyceae (28), Bacillariophyceae (24), Cyanophyceae (8) and Euglenophyceae (5). Chlorophyceae was found to be the dominant group in terms of diversity. However, the class wise representation depicted following order of dominance in terms of density of phytoplankton: Bacillariophyceae>Chlorophyceae>Cyanophyceae>Euglenophyceae. The percentage contribution of density also followed the same pattern with Bacillariophyceae contributing (50%), followed by Chlorophyceae (38%), Cyanophyceae (9%) and Euglenophyceae (3%) in a decreasing order. The most common genera encountered among all the sites included; Cymbella sp., Navicula sp., Tabellaria sp., Synedra sp., Amphora sp., Epithemia sp., Chlorella sp., Scenedesmus sp., Cosmarium sp., Tetraedron sp., Pediastrum sp., Oscillatoria sp., Anabaena sp., Phacus sp. and Trachelomonas sp. Among the sites studied, the highest value (3.45) of Shannon-Wiener diversity index was recorded at site II and lowest (3.24) at site V. The minimum value of Simpson diversity index (0.95) was recorded for site IV and a maximum of (0.96) was maintained at site II.