In Intrahepatic Cholestasis of Pregnancy (ICP) an accumulation of bile acids (BA) in the fetal compartment occurs. It is known that a BA efflux is induced by UDCA administration but the molecular basis of this transplacental transport is only partially defined. Aim of the present study was to determine if placental BCRP, able to transport BA, is regulated by UDCA in ICP. Methods: 14 pregnant women with ICP (6 untreated, 37.5±1.33 years; 8 treated with UDCA − 25 mg/kg/day, 32.14±2.16 years) and 7 agematched healthy controls (34.2±1.2 years) have agreed to participate to the study (none had gallstone disease, abnormal liver tests, liver steatosis on ultrasonography). Placentas were obtained at delivery and processed for membrane extraction. Protein expression was evaluated by standard immunoblotting techniques using actin as an internal control. Statistical differences between groups were evaluated by one way ANOVA with Dunn’s Multiple Comparison test. Results: BCRP was expressed only on the apical membrane of the syncytiotrophoblast. A significant difference was observed between the three groups (ANOVA, p = 0.01). BCRP expression was similar in cont rols and in the untreated ICP group. The administration of UDCA induced a significant increase in placental BCRP expression compared to controls (254.5±58.46 vs 100±8.002% of control, p