Hereditary deficiency of C1 esterase inhibitor (C1 INH) responsible for hereditary angioedema (HAE) is the most common hereditary complement deficiency. HAE has occasionally been reported in association with lupus erythematosus and with glomerulonephritis (GN). We report 2 cases of GN-associated C1 INH deficiency. Renal manifestations have been discovered respectively 6 to 17 years before onset of attacks. Kidney biopsy of the 1st patient showed diffuse proliferative GN with a rare and scattered wire loop pattern whereas the 2nd patient displayed a type I membranoproliferative GN. Chronic renal failure appeared in both cases and the 2nd patient recently received a kidney transplant. The onset of GN in patients with HAE outline the relationship between a genetic deficiency of complement components, the susceptibility to immune complex (IC) disease and the role of complement and its receptors in the elimination of IC.