Background: Serological diagnosis of human immunodeficiency virus (HIV) infection became available in 1985, with the rapid increase in sensitivity and specificity of enzyme-linked immunosorbent assays (ELISAs) and the supplement tests. Molecular tests for detection of HIV in the diagnosis of HIV infection in special settings and monitoring of HIV-1 infection followed this. Objective and study design. In this review it is intended to give a brief overview of the diagnosis and monitoring of HIV infection. Results and conclusion: Serological methods and molecular methods for the detection and quantitation of HIV are discussed. (C) 2001 Elsevier Science B.V. All rights reserved.