Transmission of hepatitis C (HCV) in Pakistan is a continuing public health problem; 15 years ago it was linked to the practice of reusing therapeutic instruments in healthcare settings. We sought to examine current risk factors for HCV transmission in a hospital population in Karachi, Pakistan. We enrolled 300 laboratory-confirmed HCV-positive participants and 300 laboratory-confirmed HCV-negative participants from clinics at Indus Hospital. Independent and significant risk factors for both men and women were: receiving ⩾12 injections in the past year, blood transfusions, having had dental work performed, and delivery in hospital or transfusion for women. Interestingly, being of Mohajir origin or born in Sindh province were protective. Encouragingly, a strong protective effect was observed for those that reported bringing their own needle for injections (59%). The widespread reuse of therapeutic needles in healthcare settings in Karachi remains a major driver of the HCV epidemic.