Gas chromatography mass-spectrometry (GC-MS) was used to monitor the thermo-oxidative degradation of the plain and additized mineral base oil (MBO) samples. Antioxidants used were MeOH extracts of the rice husk (RHE) and saw dust (SDE). The oxidation was performed for 6 h at 200 degrees C according to the modified Institute of Petroleum (IP) method. The results indicate that the additized MBO samples inhibited thermo-oxidation compared to the plain sample. Among the two antioxidants, the RHE showed excellent antioxidant potential compared to the SDE.