In this paper, we describe the study of the thermodynamic properties of all cycloketones, from cyclobutanone to cyclododecanone, through DSC measurements in order to reveal possible new glassy crystalline phases. This work presents revised phase diagrams of the four previously known plastic crystals of the series, namely cyclohexanone, cycloheptanone, cyclooctanone, and cyclononanone. In particular, it has been shown that the last three crystals exhibit two phase sequences, a stable one and a metastable one, which could be attained through reproducible heat treatments. Contrary to what could be expected by comparison with the cyclo-alcohol series, only two compounds, namely cyclooctanone and cyclononanone, exhibit glassy crystalline phases. Finally, the thermodynamic data related to the various phase transitions of all these compounds have been determined.