The prevalence of hepatitis C (HCV) infection among injection drug users is high and addiction-related care is increasingly being provided by GPs in Ireland. The aim of this study was to determine the prevalence and associated factors of HCV infection among injecting drug users attending general practice. The records of 571 patients attending 42 general practices in the Eastern Regional Health Authority (ERHA) area for methadone maintenance treatment were reviewed. The HCV status was recorded in 380 cases (67%). Of these, 193 had a test performed by their OP, 74 had been tested by another service and 113 had no evidence of being tested, but HCV status was recorded based on information provided by the patient himself. A total of 276 cases were identified as being HCV positive (prevalence 73%), with no difference in prevalence between the three sources of information (p=O.12). A history of injecting drug