Despite its many promising characteristics as an alternative diesel fuel, the oxidative stability of biodiesel during storage is a major concern to fuel producers. Extensive degradation can affect fuel quality with respect to viscosity, acid value, cetane number, and other properties. Fuel standards in the U.S. and Europe include the induction period (IP), which is designed to ensure that good quality is maintained during storage. However, IP is measured at 110 degrees C to accelerate the formation of radicals and induce the oxidation reaction. This work analyzes the kinetics of thermal oxidation of biodiesel from soybean oil (SME) by non-isothermal pressurized differential scanning calorimetry (P-DSC). SME samples from four different sources were evaluated by P-DSC in static mode (zero purge gas flow) under 2000 kPa pressure. Effects of adding antioxidants to SME were also examined. Heating scans were conducted at various ramp rates (beta) to determine the onset temperature (OT) of degradation. The Ozawa-Flynn-Wall analytical method was applied to infer activation energy (E-a) and pre-exponential Z-factor to calculate rate constant (k) as a function of temperature. Comparison with literature values showed that E-a and Z from static mode P-DSC were reliable with respect to oxidation of uninhibited SME. Similar analysis of data for SME treated with antioxidants suggested the nonoxidative thermal degradation dominated during heating. Thus, static mode P-DSC may not be recommended for analyzing the kinetics of thermal oxidation of SME treated with antioxidants. For uninhibited SME, results from static mode P-DSC indicated that detection of secondary degradation products by an oxidative stability or Rancimat instrument may not be a reliable indicator of the actual IP, with respect to isothermal measurement at 50 degrees C.