The reversal of enantiomeric elution order is one of the most important topics in the field of chiral separations. The elution order of the enantiomers, although rare, could be observed during the investigations of chiral discrimination in high performance liquid chromatography (HPLC). Scrutinizing these phenomena must be helpful in determining the optical purities because it is favorable to elute the minor enantiomeric impurity before the major component. In this review, several examples of such unusual behavior will be described mainly from the point of thermodynamic approaches.