The homologous series of cholesteryl methyl carbonate through cholesteryl eicosyl carbonate was synthesized from cholesteryl chloroformate and high-purity l-alkanols. The mesomorphic properties were determined optically and by differential scanning calorimetry. Cholesteric mesophases and cholesteric colors of the platelet type were found throughout the series with the exception of the pentyl and hexyl carbonates, where high freezing points were encountered. The visible spectrum was exhibited by cholesteryl heptyl carbonate through cholesteryl nonadecyl carbonate. A monotropic smectic mesophase was found in cholesteryl octyl carbonate through cholesteryl octadecyl carbonate. The plots of transition temperatures and transition heats as a function of alkyl chain length reveal relationships typical of sterols with cholesteric and smectic mesophases.