Improving access to antiretroviral therapy among injection drug users remains an urgent public health concern. We examined the time to antiretroviral therapy (ART) use among antiretroviral naive HIV-infected injection drug users who were unaware of their HIV status to examine the impact of receipt of HIV test results on uptake of ART. Time to ART use was examined using Kaplan - Meier methods, and factors associated with the time to ART were evaluated using Cox proportional hazards regression. Between May 1996 and May 2003, 312 HIV-infected individuals were enrolled into the Barriers to Antiretroviral Therapy (BART) cohort, among whom 105 (33.7%) reported not knowing their HIV status at baseline. At 24 months post-baseline, those participants who returned for test results within 8 months initiated ART at a significantly elevated rate [adjusted relative hazard = 1.87 (95% CI: 1.05 - 3.33)]. These findings demonstrate the potential to improve uptake of ART among injection drug users through targeted HIV testing and counselling initiatives that encourage the receipt of HIV test results, and suggest that strategies to improve awareness of HIV infection may improve access to antiretroviral therapy.