Research on the relationship between illicit drug use and infectious diseases have primarily focused on the major problem of heroin injection and HIV transmission. Over the past decade, however, research have shown that rates of hepatitis C infection among injection drug users have surpassed those of HIV infection. There has been little systematic study on the relationship between hepatitis C virus (HCV) and the role of methamphetamine (MA) use in the transmission of the virus. This study examined the prevalence of hepatitis C infection among a sample of 723 MA-dependent individuals who sought outpatient treatment from 1999 through 2005. Roughly 15% of the total sample and 44% of the injectors were found to be infected with HCV. Controlling for participant characteristics, we found through multiple logistic regression analyses that HCV infection was more associated with injection use, older age, and female sex. Findings suggest a need for targeted education and prevention efforts about hepatitis C among high-risk MA users, including HCV testing coupled with referrals to HCV treatments.