[19,10-3H] Metergoline was administered orally to female rats and radioactive metabolites were recovered form urine and bile. Besides unchanged drug, the presence of 1-demethylmetergoline (II) was confirmed both in urine and bile. Two other urinary metabolites were identified, namely 8 beta-aminomethyl-6-methylergoline (IX) and 8 beta-acetylaminomethyl-6-methylergoline (VI). A third metabolite, 1,6-dimethyl-8 beta-aminomethylergoline (VIII), was identified only in bile. Beside these metabolites, further polar and so far unidentified biotransformation products are present both in bile and urine, accounting for about half of the radioactivity present in these excreta.