We describe the association of crescentic membranoproliferative glomerulonephritis and hypocomplementemic urticarial vasculitis syndrome. A 39-year-old woman presented edema and proteinuria and later a non-pruritic urticarial rash. Laboratory results showed nephrotic syndrome, hypocomplementemia and positive anti-C1q antibodies. Skin biopsy disclosed leukocytoclastic vasculitis. Acute renal failure developed. Renal biopsy revealed crescentic membranoproliferative glomerulonephritis. She was treated with corticosteroids and cyclosphosphamide with improvement of the renal function and partial remission of the nephrotic syndrome. Afterwards the nephrotic syndrome relapsed, mycophenolate mofetil in monotherapy was administered with reduction in proteinuria. As far as we know only 3 cases, 2 in children and one in an adult, of crescentic glomerulonephritis and hypocomplementemic urticarial vasculitis syndrome have been reported. In our patient renal manifestations preceded urticarial lesions. We provide information on the evolution during a 42-month follow-up.