In general nephrology, HCV infection has been associated with type I membranoproliferative glomerulonephritis (MPGN type I) associated with cryoglobulinaemia. In a cohort of 399 renal transplantation (RT) recipients, 117 of whom (29%) were HCV-positive, we selected all patients diagnosed as having membranous GN or type I MPGN by graft biopsy. The prevalence of MGN was 16/399 (4%) with three recurrences, and 13 de novo cases. Only 5/16 (31%) were HCV+, not different from the general RT population. Five patients had an outcome of graft failure after 43 months. Conversely, there were 15 cases of type I MPGN (two recurrences, 13 de novo) but with eight HCV+ recipients (53%, P = 0.02). Considering only the French patients, prevalence was 44% vs 12% in the French RT population (P = 0.006). Eight patients had graft rejection after 59 months (five HCV+). In this type I MPGN subgroup, there were two positive cryoglobulins, two rheumatoid factors and four hypocomplementaemias. In conclusion, there is a clear association between HCV infection and the occurrence of type I MPGN in the allograft in renal transplantation, with terminal renal failure as an outcome.