Summary Intrahepatic cholestasis occurs most frequently in the third trimester of pregnancy. It is characterized by elevated concentrations of liver enzymes and bile acids. The main aim of the study was to analyze the changes of concentration in biochemical indicators of cholestasis during the treatment. Material and methods: The study was conducted in the group of 38 women with diagnosed intrahepatic cholestasis in pregnancy and hospitalized in Medical University Lodz, High Risk Pregnancy Clinic in 2007-2008. Treatment constituted UDCA in 750mg per 24h and Essentiale Forte 3 times a day. The concentrations in serum of AspAt, AlAt, ALP, GGTP, bile acids and bilirubin were estimated before and after 7 and 15 days of the treatment. Results: Mean concentration of AlAt was 262±16.26 U/L, AspAt 146±141.17 U/L, ALP 189±60.64 U/L, bile acids 28.6±15μmol/L, GGTP 31.5±28.15U/L but only in 28,9%was elevated. After 7 days the decrease of mean concentrations of AlAt (165±126.7 U/L) and AspAt (85±59.62 U/L) was observed. The concentration of ALP was similar to the previous results (190±71.94 U/L). After 15 days mean values of AlAt and AspAt decreased to 119±103.56 U/L and 65±46.12 U/L (p<0.001), No changes in ALP concentration were found. The concentration of bile acids decreased after 15 days to17±15μmol/L. Conclusions: The applied treatment decreased the concentration of most of biochemical markers of cholestasis. To reach the normal values of concentration of biochemical markers of cholestasis a 15-day treatment is necessary.