Anabolic steroid injectors are at risk of infection with blood-borne viruses (BBVs), but have received little attention from researchers, practitioners or agencies working in public health. In recognition of this gap, in early 1996 the Steroid Peer Education Project (SPEP) began providing part-time mobile needle and syringe distribution and health information and referral services to steroid injectors in north-eastern Melbourne. Demand repeatedly caused the project to expand, and its sole peer worker now operates Victoria-wide, five days per week. Basic information on injecting practices collected from SPEP clients showed that many were at risk of BBV infection. This led to the initiation of a collaborative research project, in which SPEP clients were tested for BBV antibodies and provided detailed information about their risk behaviours. Of 29 steroid injectors tested between May and August 1999, three (10%) had antibodies to the hepatitis C virus, and they described behaviour which could spread the virus to other steroid users. These results show that blood-borne viruses are present in the Victorian steroid injecting community, and reinforce the SPEP's commitment to reducing harm in this group.