Because of the large pharmacokinetic inter-patient variability of protease inhibitors (PI), therapeutic drug monitoring (TDM) of protease inhibitor (PI) has been proposed to improve efficacy and tolerance of PI-containing HAART. The objective of the Cophar2 trial is to evaluate the feasibility and the impact of an early therapeutic drug monitoring in PI-naive HIV-1 infected patients in order to warrant virological success and safety of HAART.