Therapeutic drug monitoring is pivotal to improve the management of HIV infection. Here, a new HPLC-UV method to quantify simultaneously maraviroc and raltegravir levels in human plasma is reported. Remarkably, this is the first method for maraviroc determination in human plasma. The volume of the plasma sample was 600 microL. This method involved automated solid-phase extraction with Oasis HLB Cartridge 1 cc (30 mg divinylbenzene and N-vinylpyrrolidone) and evaporation in a water bath under nitrogen stream. The extracted samples were reconstituted with 200 microL 50/50 of mobile-phase solution (0.01 M KH(2)PO(4) and acetonitrile). Twenty microliters of these samples were injected into a HPLC-UV system, the analytes were eluted on an analytical dC18 Atlantis column (150 mm x 4.6 mm I.D.) with a particle size of 5 microm. The mobile phase (0.01 M KH(2)PO(4) and acetonitrile) was delivered at 1.0 mL/min with isocratic elution. The total run time for a single analysis was 10 min; maraviroc and raltegravir were detected by UV at 197 and 300 nm. The calibration curves were linear up to 2,500 ng/mL. The absolute recovery ranged between 93 and 100%. The HPLC-UV method reported here has been validated and is currently applied to monitor plasma levels of maraviroc and raltegravir in HIV-infected patients.