Objective. Information on the cognitive complications of HIV/AIDS from sub-Saharan Africa, where statistics on HIV are alarming, is sparse because of lack of validated cognitive tools. This study assessed the usefulness and predictive validity of the HIV Dementia Scale (HDS) as a screening tool in HIV-positive Nigerians. Design. HIV-positive patients were randomly selected over a period of 2 months. Setting. The HIV/AIDS outpatient clinic at the University of Benin Teaching Hospital, Benin City, Nigeria. Subjects. Asymptomatic and symptomatic HIV-positive patients were compared with controls matched with regard to age, gender and level of education. Outcome measures. Cognitive performances on the modified HDS. Results. Performances on the HDS of 160 HIV-positive subjects (80 asymptomatic and 80 symptomatic) were compared with those of 80 HIV-negative controls. The mean HDS scores (maximum 12) were 10.78 (significant deviation (SD) 1.18) (HIV-negative subjects), 8.85 (SD 1.38) (HIV, asymptomatic) and 5.2 (SD 1.13) (HIV, symptomatic); p<0.01. The HDS was found to have sensitivity of 97.3%, specificity of 80.4%, accuracy of 91.9% and a positive predictive value of 91.4% and a negative predictive valu e of 93.2%.Conclusion. The HDS was shown to be a sensitive screening tool for patients with HIV/AIDS in sub-Saharan Africa, but it was insensitive to memory impairment in asymptomatic HIV-positive patients.