Henoch-Schonlein purpura (HSP) is a small-vessel vasculitis that are predominantly observed in children, affecting their skin, joints, gut and kidneys. The renal prognosis of HS nephritis is known to be worse in adults than in children. It is defined by tissue deposition of IgA. In most HSP patients, serum complement levels are usually normal. However, some authors reported abnormalities of serum complement levels in children-onset HSP. The authors report here a rare adult-onset case of HSP combined with post-infectious glomerulonephritis, especially hypocomplementemia and subepithelial 'hump'- like electron dense deposits.