To examine sexual transmission of human immunodeficiency virus (HIV) among heterosexual intravenous drug users (IVDUs), HIV antibody status of IVDUs with intravenous drug-using sexual partners (IVSPs) was compared with that of IVDUs with no IVSPs. Initial bivariate analyses indicated IVDUs with IVSPs were more likely to be HIV antibody-positive than those with no IVSPs. Analyses by gender indicated that this relationship held for men but not women. IVDUs with IVSPs also differed from those without IVSPs demographically, in drug use, and in other sexual behaviors. When effects of other variables were controlled, no statistically significant relationship was found between injection history of sex partners and HIV status for the total sample or separately for men or women.