As injection drug users (IDUs) continue to be infected by HIV, an important component of prevention efforts is the identification of factors that are associated with utilization of HIV testing programs. The purpose of this study was to identify correlates of HIV testing within the past 12 months among IDUs. A sample of 558 IDUs, recruited from street-based and community venues, completed a cross-sectional survey. Multivariate logistic regression indicates factors independently associated with having been tested recently, including social structural factors such as being incarcerated, having interactions with an HIV prevention outreach worker, and having used a case manager. Furthermore, main sex partner's testing status was positively associated with recent testing. Support of programs that are designed to serve hard-to-reach populations and target couples may be effective in increasing HIV testing among active IDUs.