Among the literature there is very little known about actual needle-sharing practices. Several small-scale ethnographic studies from relatively small samples are described. In the course of locating respondents for this study, a typology of male prostitutes was developed consisting of hustlers and call men. The Prospero Project interviewed 180 hustlers and 180 call men; the data for the call men are reported in this article. More than two-thirds of the sample had injected some drug and of those, more than 90 percent had injected methamphetamines, 59 percent had injected cocaine, and 41 percent had injected heroin. Over 70 percent reported sharing needles and a third reported needle sharing in shooting galleries or drug houses. More than 10 percent had shared needles over 100 times in shooting galleries. While the mean number of different persons with whom needles were shared during a week was 1.56, the mean number of needle sharers over an entire drug using career was nearly 150. Most IVDUs shared needles with their friends and roommates. The respondents explained their needle-sharing in terms of availability of needles, legal issues, and expense. The data do not indicate that needle-sharing is inherent in IV drug using subcultures. Analysis of the sample did not reveal ethnic or racial differences in injection of illegal drugs, needle-sharing, owning a syringe, or loaning a syringe. Needle-exchange programs could decrease the risk of HIV infection to male hustler prostitutes who are also IVDUs. 9 tables, 39 references. (Author abstract modified)