Abstract Background HIV-1 RNA is a key parameter for reliable diagnosis and treatment of HIV-1 infection. The determination of HIV-1 RNA reduces the pre-seroconversion period in the diagnosis of HIV-1 infection and supports clinical management of HIV-1-infected patients. Objectives and study design The COBAS® AmpliPrep/COBAS® TaqMan® HIV-1 Test combines automated extraction of total nucleic acids on the COBAS® AmpliPrep Instrument with real-time PCR on the COBAS® TaqMan® Analyzer, thus greatly reducing hands-on time during sample preparation and amplification/detection. The test was evaluated for sensitivity, dynamic range, precision, subtype inclusivity, interfering substances, diagnostic and analytical specificity, as well as correlation with three other commercial tests for HIV-1 RNA quantification. Results The COBAS® AmpliPrep/COBAS® TaqMan® HIV-1 Test demonstrated an assay sensitivity of 40 copies/mL, a greater than 5 log10 measuring range of 40–1.0E+07 copies/mL (1.6–7.0 log10 ) and a reliable determination of HIV-1 group M and N subtypes in EDTA plasma. Quantification results were highly correlated with those obtained by the COBAS® AMPLICOR® HIV-1 MONITOR Test v1.5, the COBAS® AmpliPrep/COBAS® AMPLICOR® HIV-1 MONITOR Test v1.5 and the VERSANT® HIV-1 RNA 3.0 assay. Conclusions The COBAS® AmpliPrep/COBAS® TaqMan® HIV-1 Test excellently satisfies the requirements for reliable quantification of HIV-1 RNA in clinical specimens by a broad linear measuring range and a fully automated quantification procedure. It is highly appropriate for therapy monitoring and routine management of HIV-1 infection.