To determine the prevalence and type of glomerulonephritis (GN) associated with hepatitis C virus (HCV) cirrhosis, we prospectively evaluated 28 consecutive Saudi patients with HCV cirrhosis for liver transplantation. Six patients (21%) underwent kidney biopsies for proteinuria, unexplained elevated serum creatinine or both. All 6 had GN, 4 had membranoproliferative, one focal segmental and one membranous GN. Immunologic and electron microscopic studies demonstrated immune complex deposition in the glomeruli. Two patients with significant proteinuria were treated with interferon alpha for 3 months with improvement in kidney and liver function. To our knowledge, this is the first report of focal segmental GN associated with HCV. This high prevalence of HCV associated GN is alarming and warrants further studies in cirrhotic and noncirrhotic patients, particularly as an indication for therapeutic intervention.