Abstract: Food habitats and activity pattern of the common otter (Lutra lutra) were studied in Coleroon and Uppanar rivers, in Pichavaram mangrove forest. In Tamilnadu, during December 1991 to March 1992. A total of 2,552 records of diurnal activities were noted through group scan of a population in fresh water habitats. Swimming or moving was a major diurnal activity, followed by resting. Scat analysis showed that fish was the major food item in the diet, followed by crustaceans.