The antioxidant activities of palm vitamin E and tocotrienols (T3) from Elaeis guineensis were investigated in model systems using distilled palm methyl ester (DME) and vitamin E-free RBD palm olein respectively. Oxidative stability was measured by the Rancimat method. Addition of 500 ppm vitamin E concentrate, which consisted of α-tocopherol (21.9%), α-tocotrienol (31.1%), γ-tocotrienol (37.7%) and δ-tocotrienol (9.3%) to DME was found to increase the oxidative stability of the substrate by a factor of about 2.6. Vitamin E-free RBD palm olein was found to be relatively unstable. Addition of 200-2000 ppm α-tocotrienol, γ-tocotrienol or δ-tocotrienol individually to vitamin E-free RBD palm olein showed that these compunds were effective antioxidants and that the activity increased with increasing concentration. At 200 ppm, a-tocotrienol improved the stability of the substrate by the factor of abount 6.3. The order of antioxidant activities of tocotrienols was found to be γ-T3 ≥ δ- T3 > α- T3 : γ-T3 had about twice the activity of α- T3.