In 2005, 16.6% of South Africans between 15 and 49 years of age were HIV positive. The advent of anti-retroviral therapy has led to improved longevity, CD4 counts and clinical well-being of people living with HIV/AIDS (PLWHA). Physical impairments, activity limitations and participation restrictions of PLWHA have profound effects on the Health-related Quality of Life and functional abilities of those with the disease, and understanding thereof may assist in the formulation of rehabilitation protocols, health care interventions as well as vocational and legislative policies. The International Classification of Function, Disability and Health (ICF) is a standardised tool, endorsed by the World Health Assembly for international use, which aims to classify functioning and disability. It is structured to assess body functions and structure, functional activities and associated personal and environmental factors.This study aimed to develop a profile of the level of functional activity, using the ICF Checklist, of an urban cohort of 45 South African individuals who are HIV positive attending an outpatient clinic at the Helen Joseph Memorial Hospital, Gauteng, South Africa. The results showed a high prevalence of physical impairments, participation restrictions and selective activity limitations and that environmental factors influence their level of ability. Specific impairments where patients had problems were mental functions (69% (n=31), sensory and pain -- 71% (n=32), digestive and metabolic functions 45% (n=20) and neuromuscular 27% (n=12). Activity limitations included major life areas' 58% (n=26), interpersonal relationships 56% (n=25), mobility 40% (n=18) and general tasks and demands 38% (n=17). Limitations in mobility were significantly associated with problems of sensory functions (p=0.05), pain (p=0.006), neuromusculoskeletal and movement-related functions (p=0.006), muscle power (p=0.006) as well as energy and drive functions (p=0.001). The study identifies the level of function and ability of PLWHA, clinical markers, and how these affect the physical, psychological and social functioning of this population.