We report the case of a prisoner for whom tattooing was the likely source of hepatitis C virus (HCV) infection. Many of the tattoos were carried out within prison using equipment that was multiply shared with other prisoners with limited access to means of disinfection. This case supports previous reports that prison is a risk factor for HCV infection and that HCV can be transmitted through tattooing. Use of unsterilised equipment for tattooing within prison must be a high-risk activity, given the high prevalence of HCV infection among those incarcerated. Harm reduction approaches are required to diminish risk in this environment.