The aim of this study was to estimate the prevalence of hepatitis C virus (HCV) and identify risk factors associated with the transmission this virus among drug users. In 2009 we performed a cross-sectional study at three facilities handling cases of drug addiction and in one prison. 259 participants were interviewed to collect socio-demographic information and determine risk factors. Anti-HCV antibodies were identified with two different immunoassays. HCV prevalence was 0%. 98% of participants used illegal drugs either orally or nasally while 4.2% injected drugs. 78% of participants reported marijuana consumption, 51% reported consumption of bazuco (Colombian variant of crack cocaine), 50.2% reported cocaine consumption and 22.8% reported amphetamine consumption. 59% had consumed drugs for more than 5 years, 60.2% had tattoos, 17.8% had piercings, and 84.9% have practiced unsafe sex. HCV prevalence was lower than reported in previous studies of drug users in Latin-America. However, we identified risk factors that would facilitate HCV infection once the virus is introduced in this population.