Capillary gas chromatography was utilized to determine the amounts of cholesterol oxidation products in butter and Cheddar cheese. Butter was analyzed for COPS at five stages of processing, and there was little or no effect due to the processing conditions. Cholesterol oxidation products that did occur originated with the raw material. Storage of butter for up to 6 mo had little effect on cholesterol oxidation. Cheddar cheese was analyzed at various stages of processing. Again, there was little effect due to processing, and cholesterol oxidation products originated with the raw material. The ripening process did not result in any appreciable increase in cholesterol oxidation products.