Data are presented on the patterns of drug use and HIV risk-taking of daily amphetamine and opioid injectors among 1245 injecting drug users who were interviewed in Sydney in 1989. About one-third of the sample had injected amphetamines during a typical month of injecting, and 12% were using amphetamines on a daily basis. Daily amphetamine injectors were younger, less well educated, and less likely to have engaged in drug treatment, but they were no more likely than daily opioid users to have shared injection equipment or to have engaged in other behaviour likely to transmit HIV. Although there seemed to be no special cause for concern about HIV risk-taking among amphetamine injectors, there was nonetheless a high prevalence of sharing injecting equipment, with over half of daily amphetamine and heroin injectors having shared in the past several months. In addition, approximately a third of amphetamine injectors were injecting on a daily basis, a pattern of use which increases the risk of developing a severe dependence syndrome, and of experiencing an amphetamine-induced psychosis.