The HIV risks associated with the sexual behaviour of drug injectors h
ave sometimes been overshadowed by the more obvious risks of injection
behaviour. In this study, 408 heroin users were interviewed in the co
mmunity; 50% were not currently in treatment and 42% had never had any
treatment contact. In addition to data on drug use, information was c
ollected on sexual risk behaviour by means of a linked anonymous quest
ionnaire (96% returned). Eighty-nine per cent of the sample had had at
least one sexual partner in the previous year and 58% had a regular s
exual partner at the time of interview. Drug users who had a sexual pa
rtner who was injecting drugs were more severely dependent upon heroin
. Twenty-three per cent of the men and 20% of the women reported havin
g had anal intercourse in the previous year. Seventeen per cent of the
women and 6% of the men had engaged in some form of prostitution. Sev
erity of heroin dependence was positively related to the occurrence an
d to the frequency of sex-for-money transactions and to the less well
recognized phenomenon of sex-for-drugs; this association with severity
of dependence applied to the women and to the men who have sex with m
en. The overall level of condom use was low in this sample, though con
dom use was more frequent among those involved in sex-for-money or sex
-for-drugs transactions. Low levels of condom use were reported even f
or such high risk activities as anal sex. Nevertheless, 55% of the her
oin users in this study perceived themselves not to be at risk or to b
e at low risk of HIV infection.