We screened 495 serum samples from 20 species of non-human primates for the antibody against hepatitis E virus (HEV). Anti-HEV IgG was detected in 84 of 232 (36.2%) Japanese monkeys, 2 of 19 (10.5%) cynomolgus monkeys, 3 of 83 (3.6%) rhesus monkeys, and 1 of 1 (100%) Taiwanese monkey, respectively. These results suggest that HEV is circulating among monkeys belonging to the genus macaca. A high prevalence of anti-HEV IgG was observed in Japanese macaques (M. fuscata) despite the fact that Japan is non-endemic for hepatitis E. It is possible that HEV can be transmitted from Japanese macaques to humans. Further, the rate of antibody positivity was found to increase with age in Japanese macaques. Seropositive macaques were found throughout Japan, but the seroprevalence rate differed among geographic regions.