The literature concerning the effect of race and ethnicity on the pharmacokinetics of psychotropic drugs is reviewed, and recommendations concerning the use of these agents are presented. While no differences in the pharmacokinetics of dosage requirements of antipsychotic drugs have been demonstrated among black, Hispanic, and white persons, Asians seem to have a lower threshold for both the therapeutic and adverse effects of antipsychotic drugs than do Caucasians. Use of lower than usual initial dosages of antipsychotic drugs in Asian patients appears to be prudent. Although ethnicity may have an effect on antidepressant drug pharmacology and dosage requirements, the available data are not sufficiently convincing to make any dosage recommendations. Claims that Asians require lower dosages of lithium than do other ethnic groups are not supported by the available evidence. Higher plasma benzodiazepine concentrations and lower drug clearance observed in Asians compared with Caucasians are consistent with clinical observations of lower dosage requirements for Asian patients; smaller than usual dosages of these agents are recommended for Asian patients. Interracial pharmacokinetic and pharmacodynamic differences for psychotropic drugs can affect clinical outcomes. Further study of this issue is warranted.