Type II cryoglobulinemia is sometimes observed in patients with HCV infection. It is also well known that some cases with membranoproliferative glomerulonephritis (MPGN) possess cryoglobulinemia, which can induce neuropathy. We treated a 73-year-old woman with hepatitis C virus (HCV) who was admitted to our department because of proteinuria. She was diagnosed as MPGN according to renal biopsy. Her ankle jerk was absent with reduced touch sensation and vibration below the knees; sural nerve biopsy revealed demyelinating neuropathy. Administration of prednisolone resulted in improved proteinuria. Cryoglobulinemia associated with HCV infection seemed to induce MPGN and demyelinating neuropathy.