This paper deals with the ants of Rabindra Sarovar, a Lake of National Importance, situated in the Southern part of Kolkata, India. A total of 29 species of ants under 20 genera and 5 subfamilies are recorded here with diagnostic characters, keys to subfamilies, genera, and species. Among these, the description of a new species, Cardiocondyla tiwarii, is also incorporated.
Moreover, to compare the diversity of ant species between unpolluted and polluted habitats, 17 species of ants under 16 genera and 4 subfamilies are recorded from the central reservation of a side road, Southern Avenue, which is exposed to constant vehicular pollution as well as man-made disturbances.