This paper aimed to characterize the ichthyofauna in the estuary of the Itajaí-Açú river, Santa Catarina, Brazil (26º 52' - 26º 55' S and 48º 37' - 48º 41' W) where four sampling stations were established, from September 1995 to August 1996. Fish were caught with drop nets, a 3 sided beach seine and a bottom net. Total of 2217 individuals belonging to 18 families were captured and 38 Teleostei species identified.