Breast cancer resistance protein (BCRP), also known as ABCG2, ABCP and MXR, is a member of the ATP-binding cassette transporter G family. BCRP functions as a biological barrier that extrudes xenobiotics out of cells. The broad substrate specificity and tissue distributions of BCRP in the body make this transporter one of the major efflux transporters in chemotherapy. Recent studies have demonstrated that BCRP exerts a great impact on drug absorption and disposition. This review focuses on the role of BCRP in pharmacokinetics as well as in vitro and in vivo strategies to evaluate hepatic/intestinal BCRP-mediated drug transports and drug-drug interactions. The impacts of polymorphism and gender difference of BCRP are also discussed.