Winter foods of the river otter (Lutra canadensis) in southern Louisiana were determined to gain an understanding of prey eaten by otters. Otters were taken by trappers in the salt marsh in southeastern Louisiana and freshwater swamp in the Atchafalaya Basin in southcentral Louisiana. Fishes were found in 83.3% of the digestive tracts from salt marsh and 83.0% of the tracts from the swamp area. Blue crabs (Callinectes sapidus) occurred in 19.8% of the digestive tracts from salt marsh and 3.8% of the tracts from the swamp area. Crayfishes (Procambarus sp.) were found in 34.% of the swamp area digestive tracts and 1.6% of the tracts from the salt marsh. Remains of mammals were found in 7.9% of the digestive tracts from salt marsh and 7.5% of the tracts from the swamp. Other foods of otters from salt marsh and their frequencies of occurrence were birds (2.4%), mollusks (1.6%) and shrimp (1.6%). Snake remains were found in 5.7% and mollusks in 3.8% of the otter digestive tracts from the freshwater swamp.