A serological survey for neutralizing antibodies to Piry (AN Be 24232) was carried out on 202 residents of the rural and urban zones of Ribeirão Preto region, State of São Paulo, Brazil. Piry are classified as vesicular stomatitis virus (Rhabdoviridae family). Several human cases of Piry virus infection have resulted from laboratory exposures. Fever, back pain, chills and headache are the symptoms of Piry infection. It is postulated that the virus is maintained in a host-vector cycle but the importance of hosts and possible vectors have yet to be determined. It was discovered that 14.3% of the sample population of Ribeirão Preto region presented neutralizing antibodies to Piry. The antibody prevalence was greater in rural zones. This sorological evidence suggests that there are endemic Piry human infections in this region.