A case of infectious gastroenteritis (GEI) caused by a non-A Rotavirus (RV) in the province of Tucumán is reported. Fecal sample analysis for group A RV by enzyme immunoassay (ELISA) gave a negative result. Polyacrylamide gel electrophoresis (PAGE) of the viral RNA showed a genomic pattern coincident with that described by Pedley for RV belonging to group C. To our knowledge, this is the first communication on the detection of non-A RV as an etiological agent of human GEI in Argentina.