The physical and chemical constants of cocoa shell fat (a by-product resulted during the production of cocoa butter at chocolate factories) were almost identical with those of cocoa butter obtained from the same cocoa beans except for their high acid value. Shell fat contained more amount of phospholipid content (as cephalin) than cocoa butter. The lipid classes were almost the same in cocoa butter and shell fat, however, the latter contained an unidentified constituent which was not found in cocoa butter. The fatty acids were determined quantitatively by GLC, and the results showed that the predominant acids in cocoa butter were palmitic, and oleic. Less amounts of capric, myristic, palmitoleic and linoleic were found in cocoa butter, whereas more amounts of these acids were found in shell fat. Cocoa butter gave higher values of stearic and myristic acids than those of shell fat. Seventeen compounds were detected by GLC in the unsaponifiable matter of both cocoa butter and shell fat from which eight were identified as C30 hydrocarbon, C32 hydrocarbon, squalene, alpha-tocopherol, cholesterol, campsterol, stigmasterol and beta-sitosterol in the two samples. The sterols were determined quantitatively, and it was found that the predominant sterol in cocoa butter and shell fat was B-sitosterol. Cocoa butter contained higher values of stigmasterol than that of shell fat, which contained increasing values of campsterol, low values of cholesterol were found in both samples. Stability of cocoa butter and shell fat towards oxidative rancidity at 100 degrees C was the same (10.5 hrs).