This work was carried out in Reserva Volta Velha, an Atlantic Forest area in Itapoá, Santa Catarina State, in southern Brazil, from September 95 to March 97. The objectives were to tipify holts of the Neotropical otter [Lontra longicaudis (Olfers, 1818)] and determine the use of sprainting sites. Monthly, we went by boat along Saí-Mirim, Braço do Norte, and Volta Velha rivers looking for otter holts, scats and footprints. The results obtained indicate that on the studied rivers, characterized by presence of silty and/or sandy bottom and absence of rocks, otters use holts among tree roots, mainly where river banks are high. In this type of environment, dense vegetation protects holt structure against erosion and high banks represent a protection against flooding. The present work corroborates the importance of the alluvial dense ombrophyllous forest to keep habitat conditions favorable to the Neotropical otter.