Membrane transporters play a key role in the intestinal absorption, tissue distribution, cellular accumulation and renal excretion of anti-HIV drugs. A clear understanding of the individual roles of these transporters is, therefore, essential if we are to attempt to design new drugs and use drug combinations that are more clinically effective. This review attempts to provide an overview of those membrane transporters considered to be relevant to the disposition and effectiveness of nucleoside reverse transcriptase inhibitors (NRTIs), non-nucleoside reverse transcriptase inhibitors (NNRTIs) and protease inhibitors (PIs). However, we are still at an early stage in our understanding of these drug transporters and their interactions with anti-HIV drugs. Rapid progress in this area is essential if the therapeutic potential of anti-HIV drugs is to be fully exploited.