Polyol esters are biodegradable synthetic lubricant base oils that can be used as an alternative to mineral oils, polyalphaolefins and diesters in many lubricant applications. These esters are not only effective lubricants, but they also have lower viscosity relative to their molecular weight, thus their major use in industrial lubrication. Therewithal polyol esters are oxidatively stable and their stability can be improved by using antioxidants. Sterically hindered phenols with 2 and 6 positions substituted with tertiary alkyl groups like butyl on the ring such as 2,6-di-tert-butyl phenol antioxidants and aromatic amine antioxidant compounds like nonylated diphenylamine are antioxidants with wide applications in industrial lubricants. Oxidative stability of oils can be determined using the Rotary Bomb Oxidation Test (RBOT). This article is the first to examine the oxidative stability-enhancing effects of 2,6-di-tert-butyl phenol and nonylated diphenylamine antioxidants on neopentylglycol (2-OH groups), trimethylolpropane (3-OH groups), trimethylolpropane complex and pentaerythritol (4-OH groups) type polyol esters using the RBOT test method. This study ascertained that synergistic effect of DTBP and BNPA on the polyol ester formulations except TMPCX.