Study of biotransformation of 2-ethyl-6-methyl-3-hydroxypyridine (2E6M3O) in rats by using high performance liquid chromatography and mass spectrometry resulted in isolation and identification of its 5 metabolites represented by dealkylated and conjugated products of transformation. In terms of manifestation of the pharmacological effect of 2E3M3O, of interest may be the identified metabolite 2E6M3O-phosphate which was found in considerable amounts in the livers of the animals. All the rest metabolites were detected only in the rat urine.