Henoch-Schönlein purpura (HSP) is an IgA-mediated small vessel vasculitis which commonly involves the skin, gastrointestinal system and kidneys. Numerous HSP triggers have been identified, and pregnancy has been reported as an exacerbating factor. After a pregnant woman had been diagnosed as having new-onset HSP, we reviewed all cases of immunofluorescence-proven HSP evaluated by the Department of Dermatology at the Johns Hopkins Hospital between 1990 and 2002, and report three cases of HSP occurring during pregnancy. Two patients developed new-onset HSP, one at 16 weeks gestation and one at 22 weeks, while the third developed a recurrence of HSP at 12 weeks gestation after 19 years of remission. We conclude that pregnancy may be a trigger for HSP onset or recurrence in susceptible individuals.