In this work, some of the most important characteristics of chiral compounds as components of the liquid crystal (LC) systems are discussed. These characteristics are the helical twisting power of chiral dopants (CDs) in the induced cholesteric (N*) mesophases, the temperature dependence of the induced helical pitch (P) quantified by the dP/dT parameter and the influence of the CDs on the N* mesophase thermal stability characterized by the dT(iso)/dC parameter. The molecular structure influence on them for several systematic series of the N-arylidene derivatives of (S)-1-phenyl- and (S)-1-benzylethylamines as well as the chiral diastereomeric 2-arylidene-p-menthane-3-ones is considered.