The factors affecting habitat selection by smooth-coated otter Lutra perspicillata were studied along the Periyar Lake within the Periyar Tiger Reserve, Kerala, India, between November 2000 and April 2001. The importance of different habitat features influencing habitat selection was assessed using ordination technique. The presence of holts, spraint sites, grooming sites and footprints were considered as good indicators of the use of an area by the otters. For foraging, otters selected less rocky areas of the shallower parts of the lake, which are narrower and slanting. The number of streams joining these areas was more than on the other stretches of the lake and the bankside vegetation was dense. The deeper and wider areas of the lake were avoided. Holts were found in a variety of habitats, such as grass and Lantana thickets, rock crevices and under fallen logs and roots of standing trees at an average distance of 18 m from the water level. Grooming sites were characterized by high sand content and nearness to water.