The direct detection and quantitation of human immunodeficiency virus type 1 are becoming increasingly important for diagnosis and viral load determinations in human immunodeficiency virus type 1 infection. Traditional molecular-based assays such as Southern, Northern, and in situ hybridization have had limited application in this area due to the relatively low number of proviral copies per cell, the low percentage of infected cells, and transcriptional dormancy in many of the infected cells. Recent technological advances in polymerase chain reaction assays promise a number of useful applications in the clinical research and clinical laboratory setting.