Chlorpromazine (CPZ) equivalents are often used as a relative measure of the antipsychotic potency of neuroleptics. We review the CPZ equivalents of 33 neuroleptics and illustrate why imprecisions or discrepancies will be difficult to eliminate from these values. We nevertheless underline that CPZ equivalents can be clinically useful, since they facilitate the choice of doses of different neuroleptics that should induce comparable antipsychotic effects.