The diagnosis of systemic lupus erythematosus (SLE) was a leading initial consideration in 2 patients with rash, arthritis and hypocomplementemia. One patient also had leukopenia and thrombocytopenia. Spontaneous regression occurred. In both patients antinuclear antibodies were negative. Serologic studies indicated recent human parvovirus B19 infection. We propose adding human parvovirus B19 infection to the list of conditions that may masquerade as SLE.