Psychiatric disorders are more common in people living with HIV/AIDS (PLWHA) than in the general population and they exert a significant effect on many health-related outcomes. Low levels of mental health literacy and stigma may contribute to delayed treatment seeking and poorer outcomes. A convenience sample of 400 HIV-positive respondents were selected from three health clinics in Cape Town. Respondents' mental health literacy and attitudes towards psychiatric disorders were investigated. Psychiatric disorders were viewed as stress-related 70-91% of the time. Seeking help from a medical professional was often endorsed as an effective treatment option, while taking medication was rarely endorsed. Respondents held negative attitudes towards people with psychiatric disorders. In particular, people with substance abuse and PTSD were stigmatised more than those with depression and schizophrenia. The understanding of the psychobiological nature of psychiatric disorders and of existing effective treatments in PLWHA in South Africa is limited. Interventions designed to increase mental health literacy and reduce the stigma associated with psychiatric disorders may increase the likelihood of PLWHA seeking treatment should they suffer from these conditions.