The petechial glove and sock syndrome is a recently described febrile dermatosis characterized by acral pruritus, edema, pain, petechiae, and an enanthem of petechiae and erosions; these features suggest a viral origin. We report a typical case in a 36-year-old woman. IgM antibodies to human parvovirus B19 (PVB19) were present, and acute and convalescent IgG antibodies demonstrated seroconversion, which suggested recent infection with PVB19. Results of tests for other viral and bacterial agents were negative. These results strongly implicate PVB19 as an etiologic agent in the petechial glove and sock syndrome.