The characteristics and prevalence of hepatitis C virus (HCV)-associated glomerulopathy remain to be determined. To analyze the relationship between HCV infection and glomerulopathy, we enrolled three groups of individuals or patients. The first group consisted of 7776 individuals who were seen for routine checkups. The second group consisted of 86 patients with chronic hepatitis C, 40 patients with chronic hepatitis B, and 51 patients with non-viral liver diseases. The third group consisted of nine patients with HCV association glomerulopathy who underwent renal biopsy. Of the 7776 individuals undergoing medical checkups, 142 (1.8%) were positive for HCV antibody. The positive rate of proteinuria was significantly higher (P<0.030) in individuals with HCV antibody (2.1%) than in those without the antibody (0.6%). Abnormal levels of serum creatinine (5.8 vs. 0%, P=0.025) and complications of cryoglobulinemia (45 vs. 5%, P<0.001) were significantly more common in the 86 patients with chronic hepatitis C (5.8%) than in the 91 patients with other liver diseases. All patients with abnormal levels of serum creatinine had concomitant cryoglobulinemia. Of the nine patients with histologically proven HCV-associated glomerulopathy, four had cryoglobulinemia (all were type II). Elevations of serum creatinine level (4/4 vs. 0/5, P=0.048) and a glomerular legion of membranoproliferative glomerulonephritis (3/4 vs. 0/5, P=0.048), a severe type of glomerulonephritis, were more common in the four patients with cryoglobulinemia than in the remaining five patients. In conclusion, HCV infection was found to be significantly associated with glomerulopathy. In addition, the presence of cryoglobulinemia, which usually accompanies membranoproliferative glomerulonephritis, was found to be an indicator of renal insufficiency in patients with HCV-associated glomerulopathy.