Introduction. Simian parvovirus (SPV) causes severe anemia in immunocompromised macaques. The closely related erythrovirus, parvovirus B19, causes anemia in susceptible humans and can be grown in human bone marrow mononuclear cells in vitro. We hypothesized that SPV may infect humans and replicate in human bone marrow mononuclear cells. Methods. Serum samples from handlers of an SPV-seropositive macaque colony were tested by Western blot for evidence of antibodies to SPV. SPV capsid protein was expressed in insect cells, and SPV was cultured in human and macaque bone marrow mononuclear cells. Results. Fifty-one percent of exposed handlers (n = 65) were found to be SPV seropositive, compared with 35% of nonexposed individuals (n = 124). In 17% of exposed handlers, compared with 6% of nonexposed individuals, antibodies were directed to SPV but not to B19. SPV capsid proteins, like those of B19, self-assembled to form parvovirus-like particles, and these capsids, like B19 capsids, bound to globoside, suggesting that globoside is also the receptor for SPV. We demonstrated that SPV could replicate in vitro in both human and macaque bone marrow mononuclear cells and that it was cytotoxic to erythroid progenitor cells. Conclusions. Our data suggest that SPV may infect human bone marrow mononuclear cells in vitro and in vivo and should be considered a potential zoonosis.