【Abstract】 Objection To delineate the incidence and risk factors for sero-conversion to positive anti-HCV antibody in maintenance hemodialysis (HD) patients. Methods From June 1998 to December 2008, 2080 HD patients in our hemodialysis unit were followed up, and anti-HCV antibody assay by ELISA was performed every 6 months in the same laboratory. Results From results of the 22 assays at an interval of 6 months for every patient, the sequential prevalence rate of anti-HCV antibody was 54.7%, 53.8%, 52.6%, 53.0 %, 51.2%, 45.9%, 45.5%, 48.2%, 35.6%, 33.7%, 33.7%, 31.7%, 30.4%, 28.4%, 27.2%, 24.5%, 20.8%, 19.4%, 16.6%, 14.4%, 15.3% and 15.2%. During the follow-up period for 126 months, anti-HCV antibody became positive in 225 patients, of whom 58 had not been treated with transfusion. Sero-conversion to positive anti-HCV antibody was found in 49 (4.5%) of the 1086 patients followed up for 1-12 months, in 29 (6.9%) of the 421 patients followed up for 13-24 months, in 35 (11.9%) of the 196 patients followed up for 25-48 months, in 32 (28.1%) of the 114 patients followed up for 49-60 months, in 27 (35.1%) of the 77 patients followed up for 61-72 months, in 22 (38.6%) of the 57 patients followed up for 73-84 months, in 15 (46.9%) of the 32 patients followed up for 85-96 months, in 9 (56.3%) of the 16 patients followed up for 97-108 months, and in 6 (54.5%) of the 11 patients followed up for 109-126 months. Conclusion Hemodialysis may be responsible for the HCV transmission either due to the common use of a dialysis machine or to the unawareness of isolation procedures for HCV-infected patients. Therefore, sterilization manipulations and strict isolation for HCV-infected patients are of great importance for the prevention of HCV transmission among hemodialysis patients.