The sensitivity and specificity of an enzyme-linked immunosorbent assay (ELISA), absolute numbers of T-helper cells, and T-helper: T-suppressor cell ratios were compared in asymptomatic controls and IgG Western blot-confirmed patients with the acquired immune deficiency syndrome (AIDS) in Kinshasa, Zaire, between August 1984 and May 1985. Two hundred sixteen (97.7%) of 221 IgG western blot-positive AIDS patients and 4 of 97 (4%) controls were ELISA-positive, 3 of whom were Western blot-positive. The sensitivity and specificity of the ELISA was 97.7% and 99.0%, respectively, compared to Western blot results. Detection of the human immune deficiency virus using absolute number of T-helper cells (<400 cells/mm3) was as sensitive (98.2%), but less specific (90.7%). A T-helper: T-suppressor ratio of <0.9, had a sensitivity of 97.3%, and specificity of 94.8%. The ELISA test had the highest predictive value and greatest utility in an African clinical setting for detecting HIV infected patients were a wide range of other immunocompromising diseases are seen.