Although pig and wild boar are considered to be the reservoirs of hepatitis E virus (HEV) in Japan, the spread of HEV to other animals is unknown. Serum samples from 84 mongooses (Small Asian mongoose; Herpestes javanicus) collected in Okinawa, Japan were examined for antibodies to HEV by enzyme-linked immunosorbent assay and RNA was analyzed by reverse transcription-polymerase chain reaction. Seven (8.3%) of 84 mongooses were positive for IgG antibodies to HEV, and the antibody-positive rate increased with body weight and size, whereas HEV RNA was not detected in these samples. These results are consistent with the possibility that mongooses in Okinawa are occasionally infected with HEV; however, they are not considered the major zoonotic reservoir of HEV.