Unsaturated lipids when exposed to air at room temperature undergo a slow autoxidation. When fullerene C 60 was dissolved in selected lipids (ethyl oleate, ethyl linoleate, linseed oil and castor oil) the spectrophotometric analysis shows that the oxidation is concentrated to C 60 which is converted to an epoxide C 60O. Thus, fullerene C 60 displays antioxidant activity not only when dissolved in unsaturated lipids but also, more generally, when dissolved in unsaturated solvents subjected to autoxidation like, for example, in cyclohexene. The behaviour of C 60 in ethyl oleate has been compared with that of the known antioxidant TMPPD (N,N′,N,N,′-tetramethyl-p-phenylenediamine) in ethyl oleate. The mechanism of the antioxidant action of C 60 in lipids has been proposed. The kinetics of C 60 oxidation in lipids was determined spectrophotometrically both at room temperature in the dark and under UV irradiation. The oxidized products derived from C 60 photo-oxidation in lipids have been identified.