To evaluate the prognostic value of provirus copy number through quantitative DNA polymerase chain reaction (PCR) in early stages of human immunodeficiency virus type 1 (HIV-1) infection, 42 untreated and asymptomatic HIV-L-seropositive subjects with baseline CD4⁺ cell counts >200 × 10⁶/L were included in a prospective study and followed over a median of 27 months. Disease progression was defined as decrease in CD4⁺ cells to <200 (14 events). At enrollment, provirus copy number was associated with CD4⁺ cell count and percentage, serum IgA, and p24 antigenemia. Elevated provirus copy number above 20 allowed identification of patients at high risk of a subsequently decreasing CD4⁺ cell count, even after adjusting for baseline CD4⁺ cell count (P = .003). Measuring provirus copy number by PCR at early stages of HIV-1 infection could offer a useful early means to predict progression to AIDS.