Drug disposition is highly dependent on the interplay between drug metabolism and transport in organs such as the intestine, kidney, and liver. Genetically determined variation in drug transporter function or expression is now increasingly recognized to have a significant role as a determinant of intersubject variability in drug response. Similar to the discoveries of functional genetic variations in drug efflux transporters, such as multi-drug resistance proteins 1 and 2, there have been considerable advances in the identification of single nucleotide polymorphisms in transporters that facilitate cellular drug uptake. Among the uptake transporters, members of the organic anion-transporting polypeptides and organic anion transporters can mediate the cellular uptake of a large number of structurally divergent compounds. Accordingly, functionally relevant polymorphisms in these transporters may contribute to interindividual and interethnic variability in drug disposition and response. In this review, recent progress relating to pharmacogenomics of organic anion transporters will be outlined along with a compilation of currently known genetic polymorphisms.