A HPLC Method is described for the determination of tocopherols and tocotrienols in human diets and plasma. After a room-temperature saponification diet samples were extracted with n-hexane. A direct hexane extraction was used for plasma samples. Using a normal-phase column at elevated temperature and a fluorescence detector complete separation of all four tocopherols, alpha-, beta-, gamma-tocotrienols and BHA and good reproducibility and sensitivity were obtained. The recovery of tocopherols added to diet samples was 99% for alpha-tocopherol, 95% for beta-tocopherol, 99% for gamma-tocopherol and 80% for delta-tocopherol. The recovery of alpha-tocopherol added into plasma was 99%.