A suspected nosocomial outbreak of parvovirus B19 infection in a maternity ward was investigated in February 1994. Questionnaires were administered and sera collected from maternity ward staff (n = 91), other ward staff in the same hospital (n = 101), and maternity ward staff at a nearby hospital (n = 81). Blood donors (n = 265) were used as community controls. Recent infection (parvovirus B19 IgM positivity) in susceptible persons (parvovirus B19 IgG-negative or IgM-positive) was common among all 4 groups (23%-30%). This high rate of recent infection occurred during a large community outbreak of fifth disease. Environmental samples collected from a room where a stillborn parvovirus B19-infected fetus was delivered were positive for parvovirus B19 DNA. Thus, this suspected nosocomial outbreak actually reflected transmission outside the hospital, but contaminated environmental surfaces were identified as one potential source for transmission of parvovirus B19.