The 6th International Workshop on Clinical Pharmacology of HIV Therapy convened at the Fairmont Le Château Frontenac in Québec, Canada on April 28-30, 2005. More than 170 participants registered for this workshop, demonstrating the continued interest in exploring and understanding the complexities of antiretroviral pharmacology. The purpose of this meeting was to present and discuss research related to antiretroviral pharmacokinetics, pharmacodynamics, drug interactions, therapeutic drug monitoring and the assays necessary for measuring antiretroviral concentrations. This article highlights some of the 22 oral and 98 poster presentations that were presented at this meeting.