Acute generalized exanthematous pustulosis (AGEP) is a reaction pattern with characteristic clinical features. AGEP typically presents with at least dozens of non-follicular sterile pustules in addition to fever and elevated blood neutrophils. The onset is acute and pustules tend to resolve spontaneously. We herein report the findings of a 33-year-old female who presented with erythema on her elbows and dorsal thighs. Before onset, she did not receive any medications. She had no history of psoriasis, had not touched mercury, did not use tampons and was not pregnant. On the third eruptive day, she developed more than 100 non-follicular pustules in diffuse edematous erythema on her trunk and extremities, predominantly involving the intertriginous areas and she also demonstrated high fever. Her temperature returned to within the normal limits on the fourth eruptive day and the pustules thereafter dramatically vanished until the fifth eruption day. Enzyme immunoassays (EI) were performed for anti-virus antibodies and revealed a seroconversion of antihuman parvovirus B19-specific immunoglobulin (Ig)G antibodies, thus indicating a primary human parvovirus B19 infection. The most frequent causes of AGEP seem to be a drug reaction and enterovirus infection. However, AGEP has not yet been reported to be associated with human parvovirus B19. We speculated that human parvovirus B19 may therefore be one of the causative agents of AGEP.