Hepatitis C virus infection is associated with several glomerular diseases, most commonly cryoglobulinemic glomerulonephritis, which is typically secondary to type II mixed cryoglobulinemia. We present a patient with hepatitis C virus infection and cryoglobulinemic glomerulonephritis secondary to type I (monoclonal) cryoglobulinemia that is likely related to a concurrent hepatitis C virus infection–associated lymphoproliferative disorder. We list the differential diagnosis of cryoglobulinemic glomerulonephritis.