Forty-two 60-d-old rats were fed a vitamin E-deficient diet for up to 8 wk and the kinetics of alpha-tocopherol depletion were measured in nervous tissue and various organs. In most tissues examined, including the sciatic nerve but not the cerebellum, the disappearance was biphasic, suggesting the existence of two pools of vitamin E. In forebrain the disappearance was poorly biphasic. After an 8-wk period of vitamin E deprivation, forebrain, cerebellum, sciatic nerve endoneurium, liver, heart, muscle, testes and serum vitamin E concentrations were 51, 64, 65, 10, 20, 20, 40 and 19%, respectively, of initial values.