It is increasingly recognised that uptake transporters of the organic anion-transporting polypeptide (OATP) family play important roles in drug absorption, distribution and excretion. They are expressed in a variety of different tissues, including gut, brain, kidney and liver. Substrates of OATPs include several endogenous substances, such as bile salts and hormones, and drugs such as HMG-CoA reductase inhibitors (e.g., pravastatin), cytotoxic drugs and antibiotics. Recent advances in the pharmacogenetics of OATPs have demonstrated that variations (polymorphisms) in genes encoding human OATPs can explain parts of the interindividual variability in the pharmacokinetics of drugs and, thus, contribute to the interethnic and interindividual variability in drug response. This review focuses on consequences of these genetic variations and summarises in vivo as well as in vitro analyses demonstrating the impact of polymorphisms in genes encoding OATPs on transport and pharmacokinetics of drugs.