Four base oils of different chemical nature were subjected to an oxidation processes using the ASTM D 8206-18 method. On the basis of these oils, three different types of lubricating greases were manufactured: lithium, silica and polyurea lubricating greases. Samples of the lubricating greases were also oxidized in accordance with ASTM D 8206-18. The obtained values of thermal oxidation stability were compared. FTIR spectra were recorded for all the samples after the oxidation process. Based on an analysis of the results of oxidation stability tests and the FTiR spectra (including differential ones), the groups of base oils and lubricating greases produced with their participation that demonstrate the best and the worst resistance to degradation processes as a result of the oxidation reaction were determined.