Cholesteryl acetylferulate (99.61%) shows complicated thermal aspects of behavior with DSC: a double peak of cholesteric-isotropic liquid transition on first heating, a cholesteric-smectic A transition on cooling, and two types of cold crystallization through a glass transition on second heating. The stability of the solid polymorphs generated from the cold crystallization is discussed from the thermodynamic point of view. Cholesteryl cinnamate examined for comparison showed no double peak in the cholesteric-isotropic liquid transition. It also showed neither glass transition nor cold crystallization phenomenon. The characteristics were independent of whether the purity was 99 or 100%. From the above results, it can be concluded that the presence of extra functional substituents on the phenyl radical of cholesteryl cinnamate is causative of the complicated thermal properties of cholesteryl acetylferulate.