We investigated the relationships among gender, drug use, and perceived social support in 176 HIV positive patients recruited with their informal caregivers in HIV clinics. Perceived caregiver support, emotional support, tangible support, and conflict were assessed. Current drug use was defined as heroin and/or cocaine use within 6 months prior to baseline. Gender was not significantly associated with any of the four outcomes. Current drug users reported significantly higher conflict in social relationships than nonusers, but was not significantly associated with the other three outcomes. However, significant heroin/cocaine use by gender interactions were observed; specifically, the negative associations between current drug use and perceived caregiver and emotional support were stronger among females than males. We concluded that recent heroin/cocaine use may be associated with dissatisfaction in perceived social support from most sources, with the strongest relationships amongst drug using females.