Henoch-Schönlein purpura (HSP) is an IgA-mediated small vessel vasculitis with a predominant cutaneous involvement. We assessed adult patients with HSP to identify the clinical and histopathological features and evaluate predictive factors of relapse. We reviewed the records of 29 adult patients with HSP who presented at our department between 2002 and 2009. Adult HSP was confirmed by skin biopsy showing leukocytoclastic vasculitis and direct immunofluorescence showing IgA deposit. Among the 29 patients (15 men, 14 women; mean age 36.2 years old), renal involvement was initially found in 22 patients (75.9%). They were divided into 2 groups according to the presence or absence of relapse. We compared clinical and histopathologic differences between 15 patients with relapse and 14 patients without relapse. By univariate analysis, older age at onset, persistent rash, abdominal pain, hematuria, and underlying disease at the onset of HSP are significantly related to relapse. Among the histopathological variables, severity of leukocytoclasis and absence of IgM deposit on the vessel walls are significantly associated to relapsing disease (P < 0.05). Our results are significant, because, they may help to understand the predictive factors related to relapses of HSP in adults. Further studies are necessary to identify whether more aggressive treatment in adults with HSP with these predictive factors can prevent relapse and severe renal sequelae.