Individuals who use illicit stimulants, primarily cocaine and methamph
etamine, engage in substantial amounts of HIV-related sexual risk beha
viors when under the influence. This paper presents the idea that redu
ctions in stimulant use consequent to drug treatment makes stimulant d
rug treatment an important HIV prevention tool for this high-risk popu
lation. Data are presented to describe many of the HIV-related sexual
risks reported by out-of-treatment methamphetamine users and by cocain
e and methamphetamine abusers at treatment entry and six months post t
reatment entry. Overall, our findings demonstrate that following initi
ation of a treatment episode, stimulant abusers demonstrate significan
t and relevant reductions in HIV-related sexual behaviors, primarily b
y reducing the number of sexual partners. Rea sons for why stimulant t
reatment corresponds to HIV transmission risk reductions and suggestio
ns for implementing prevention messages in treatment settings are offe
red.