BACKGROUND: The disease course of adult immunoglobulin A (IgA) vasculitis (IgAV; Henoch-Schönlein purpura) has not been well defined. METHODS: In a retrospective survey, we studied 85 adult IgAV patients with extended follow-up (median 43 months) for 67 patients. RESULTS: Only 33 of 67 (49%) achieved complete remission. Ongoing renal disease was the most common persistent organ manifestation, but extra-renal disease activity was also present in >50% of patients not achieving complete remission. Twenty-nine of 67 (43%) had relapsing disease, with 18/67 (27%) experiencing several relapses. Skin disease was the most common feature in relapsing patients, followed by nephritis. At 4 years of follow-up, 6 of 29 (21%) experienced progressive disease and 10/29 (34%) relapsing disease. Five of 67 (7%) developed nephritis after diagnosis, within the first 6 months of follow-up. At final follow-up, 10 of 67 (15%) had chronic kidney disease Stage ≥G3a, 18 (27%) haematuria and 13 (19%) proteinuria. No therapy appeared particularly effective and only 6/17 patients treated with mycophenolate mofetil experienced a good response. CONCLUSIONS: The disease course of adult IgAV is different from that seen in children, with higher frequency of persisting and relapsing disease. Renal disease is the main determinant of ongoing disease activity, but extra-renal features were seen in >50% of patients with chronic disease activity. No clear conclusions on use or choice of immunosuppressive agent could be made based on our experience.