The use of biodiesel has grown year-by-year, mainly due the low emission of pollutant gases. In addition, the raw materials used in its production are renewable, different from petroleum fuel. However, the biodiesels are more susceptible to oxidative degradation during the storage period, what damages the product quality. According the actual legislation, the use of antioxidant additives is necessary in order to provide a good resistance against oxidative reactions, which can be determined through accelerated oxidation tests, known as Rancimat method. The synthetic antioxidants tert -butylhydroquinone and butylated hydroxytoluene are among the most used, but several natural antioxidants could also be used. Thus, this work aims to evaluate the antioxidant properties of some natural antioxidants by using the Rancimat method. Two commercial biodiesel samples were added of three types of antioxidant at different levels of concentrations and submitted to accelerated oxidation in order to determine the induction periods. Different from vitamin E and grape seed oil, the eugenol additive presented the highest induction periods, being the most promising antioxidant additive for using in commercial biodiesel. DOI: http://dx.doi.org/10.17807/orbital.v10i1.1027