Background: We sought to evaluate the potential association between binge drug use and HIV seroconversion and subsequently, risk factors associated with binge drug use among a cohort of IDUs. Methods: We performed analyses of: 1) associations with HIV seroconversion and 2) associations with binge drug use among participants enrolled in the Vancouver Injection Drug Users Study (VIDUS), a prospective cohort of IDU. Since serial measures for each individual were available, we undertook a time-updated Cox regression analysis to detect associations with HIV incidence and variables potentially associated with binge drug use were evaluated using generalized estimating equations (GEE). Results: Overall, 1,548 IDU were enrolled into the VIDUS cohort between May 1996 and May 2003. There were 1,013 individuals who were HIV seronegative at enrolment and had at least one follow-up visit, 125 (12%) became HIV positive during the study period for a cumulative incidence rate of 14% at 64 months after enrolment. In the final multivariate model, binge drug use (Adjusted Hazards Ratio: 1.61 [CI: 1.12, 2.31]) was independently associated with HIV seroconversion. In sub-analyses, when we evaluated associations with binge drug use in GEE analyses, borrowing (Odds Ratio [OR]: 1.50 [CI: 1.33 - 1.69]) and lending (OR: 1.78 [CI: 1.57 - 2.01]) syringes, sextrade work (OR: 1.18 [CI: 1.24 - 1.57]), frequent cocaine (OR: 2.46 [CI: 2.25 - 2.69]) and heroin (OR: 1.21 (CI: 1.10 - 1.32)] injection were independently associated with binge drug use and methadone (OR: 0.82 [CI: 0.75 - 0.89]) was protective against binge drug use. Conclusions: Our study identified an independent association between binge drug use and HIV incidence, and demonstrated several high-risk drug and sexual risk practices associated with bingeing. Given the unaddressed public health risks associated with bingeing, a public health response protocol must be developed to minimize the personal and public health risks associated with the binge use of drugs. [abstract]