OBJECTIVE To review the indications, safety and efficacy of psychotropic medications used in preschoolers. METHODS Proprietary prescription-use databases indicate that practitioners are prescribing psychotropic medications for preschool patients at an increasing rate. A Medline search was conducted using drug exposure for children below the age of 6 years to identify efficacy and safety reports of these agents in the preschool age-group. RESULTS The search yielded 22 reports that mention exposure to medications, including maternal exposure, accidental overdose, and adverse events in preschool children. Safety issues highlight the age-specific vulnerabilities of this age-group, including hepatotoxicity from valproic acid, among others. In addition, the prominence of adverse-event responses in this age group may be related to polypharmacy not seen in school-age children or adolescents. Less than a dozen controlled efficacy studies of psychotropic agents were identified for children in the preschool age-group. These are limited by the small numbers of subjects in the reports. Only 2 disorders described in the Diagnostic and Statistical Manual of Mental Disorder (DSM-IV), attention-deficit hyperactivity disorder (ADHD) and autistic disorder, are mentioned. The Food and Drug Administration (FDA) approved psychotropic medications for preschoolers but limited their use to medical purposes, not psychiatric, with the exception of use for ADHD. CONCLUSIONS Because data about psychotropic drug safety and efficacy in adults have not been extended to children, new psychopharmacological research is required before clinicians can use these agents to treat psychiatric disorders in the preschool age-group.