2330 pregnant women were admitted to the 2nd Department of Pregnancy Pathology at the Polish Mother's Memorial Hospital (PMMH) in Lódź, Poland, during the period from 28th March, 1989 to 30th June, 1991. Out of the group 1055 pregnancies were treated because of the risk of premature delivery (45.28%). In five (5) cases a significant rise of ALAT and AspAT aminotransferase activity occurred during fenoterol therapy. Laboratory tests excluded infectious etiology in the rise of the enzymes in question (no markers typical for HBV, HAV infection). Toxic injury of hepatic cells being suspected, fenoterol therapy was withdrawn, followed by a decrease of aminotransferases activity to normal values in those five (5) cases. No increase in the activity of ALAT and AspAT occurred in further follow up of the pregnant women in pregnancy and in puerperium. Since no other hepatotoxic factors appeared, it may be assumed that a chronic administration of fenoterol can cause transient injuries of hepatic cells. For this reason all pregnant women treated with betamimetics require examinations of the liver.