The purpose of this study was to characterize the injection and sexual risk behaviors of a cohort of active drug injectors who have initiated injection within the past 4 years and to compare their behaviors with the risk behaviors of long-term injectors who have been injecting drugs since 1984. A stratified, network-based sample was used to recruit injection drug users from the streets in Miami-Dade, Florida. After screening for eligibility, which included a urine test to confirm current drug use, participants were administered a structured questionnaire that included basic demographic information, drug-use history, and HIV risk behavior practices. Both injector groups displayed a high level of HIV injection risk behavior. Although new initiates into injection demonstrated lower risk behavior than long-term injectors at the first injection episode, the current risk behavior between new and long-term injectors is similar.