To assess how injection practices may have changed during the course of the AIDS epidemic, active intravenous drug users (IVDUs) recruited from the community were asked to report year of first injection as well as specific details about the first 3 months after initial injection: frequencies of injection, using sterile needles, sharing needles and other equipment. For the analysis, the users were sorted into successive cohorts of initiation (by year of first injection), and tests for trends were completed using Mantel-Haenszel statistics. Among the 421 IVDUs who reported first injection between 1982 and 1987, the use of new sterile needles to self-administer drugs increased (p<. 05) along with its corollary behavior (i.e., using equipment one is sure that no one else had used before). Conversely, there was a decrease in the proportion of those who always used equipment previously used by another IVDU (p<. 05) and a decrease in the number of needle-sharing partners (p<. 01). Over the 6 years, heroin as first drug decreased and cocaine increased (p<. 01). Although these data are from a cross-sectional interview study, they suggest a shift toward lower risk practices among new IVDUs between 1982 and 1987. The shift from heroin to cocaine is compatible with other evidence on the cocaine epidemic.