The pharmacokinetics of Vaccinium myrtillus anthocyanosides (VMA) have been investigated in male rats. After intravenous administration anthocyanosides undergo a rapid body distribution and their disappearance from the blood is suitably fitted by a three-compartment pharmacokinetic model. The elimination occurs mostly through urine and bile. After a single oral administration the plasma concentrations of anthocyanosides reach peak level after 15 min and then rapidly decline within 2 h. The extent of cumulative urinary and biliary elimination together with the gastrointestinal recovery demonstrates an absorption of about 5%. No hepatic first-pass effect has been observed. Despite of the modest gastrointestinal absorption and the low absolute bioavailability (1.2% of the administered dose), the plasmatic peak levels (2-3 micrograms/ml) measured after the oral treatment are in the range of biological activity reported for these substances.