Our aim was to ascertain current guidelines and clinical practices prevalent in HIV treatment centres in the North Thames Region of England on the care of patients co-infected with HIV and hepatitis B or C. A self-completed postal survey of clinic guidelines and retrospective case-note reviews was performed. Fifteen of the 27 units completed the survey and generally had clinic guidelines consistent with current national guidelines. Stated policy was usually to screen HIV patients for hepatitis B virus (HBV) and hepatitis C virus (HCV) and to offer specific therapy for the hepatitis as well as the HIV. Many units were unable to contribute cases to the case-note review, probably through lack of case-identification, and therefore 11 units contributed 27 case-note reviews on HIV/HBV and five units contributed 11 case-note reviews on HIV/HCV. Fifty-six percent (25/45) of patients of HBV patients were HBeAg+ve and 88% (22/25) of these had received specific hepatitis B therapy although for 59% (13/22) this was with lamivudine as part of a highly active antiretroviral therapy regimen. None of the HIV/HCV patients had received or been referred for HCV-specific therapy. Testing for hepatitis A immunity in HBV or HCV patients with a view to vaccination was done in only 50% although 96% of HIV/HCV patients had been screened for HBV. There are significant differences between the clinics' intended and actual management of HIV and chronic viral hepatitis co-infection.