During 2001, Greater Glasgow National Health Service (NHS) Board undertook a patient notification exercise in a Glasgow dental practice following the admission, by the dentist, of the use of unsterilized dental equipment on patients. Four thousand and eighty-nine exposed patients were identified; of these, 1696 contacted the NHS helpline and 1005 were counselled and screened for hepatitis C virus (HCV), hepatitis B virus (HBV) and human immunodeficiency virus. One patient showed evidence of previous HBV infection and 13 had antibodies to HCV. Molecular investigation of the HCV isolates indicated no significant associations. The investigation found no evidence of patient-to-patient transmission of HCV among patients attending the practice of a dentist who admitted periodically using unsterilized equipment.