In Thailand it lives in Phru Toa Daeng Peat Swamp Forests (Kanchanasaka et al. 1998). In Viet Nam it has also been reported from the low lying peat swamp forests of U Minh Thuong Nature Reserve in Mekong Delta (Nguyen et al. 2001, Sage et al. 2004) and from Cambodia it has been reported from Tonle Sap wetlands (Poole 2003, Heng 2007). It inhabits freshwater and coastal areas, especially mangroves in Indonesia. Wayre (1974, 1978) considered that the Hairy-nosed otter mainly inhabited mountain streams above 300 m, Medway (1969) recorded it in the sea off Penang.

The hairy nosed otter principally predate on fish (85.5%) followed by water snake and they also supplement their diet with frog, lizard, turtle, crab, mammal and insect, although these may not be that important in its diet (Kanchanasaka 2007). Fish belonging to the families Channidae, Belontiidae, Anabantidae, Notopteridae, Synbranchidae, Clariidae, Nandidae, were identified in the fecal samples from Thailand. The main prey selected were three-spot gourami (Trichogaster trichopterus), common climbing perch (Anabas testudineus), and snakeheads (Channa sp) (Kanchanasaka 2007).

Not much is known about its breeding behaviour but there is indication that it breeds in November-December in the Mekong delta. Kanchanasaka et al. (2003) found that gestation was around 2 months as with other otters, and cubs were seen in December to February, and one family observed consisted of both parents and a cub.