Pervasive developmental disorder is one of the most severe clinical disorder in child psychiatry and is associated with deviancies in multiple areas of development. Medication does not cure pervasive developmental disorder and its effectiveness is generally nonspecific. But psychopharmacological treatment can be important for some children with pervasive developmental disorder and can make many young autistics more amenable to behavior modification and education. Haloperidol, the most widely studied antipsychotics, was statistically and clinically superior to placebo, and furthermore, was known to facilitate the positive functioning such as, discrimination learning and imitative communication, without side effects. However, administration of haloperidol is associated with drug related dyskinesia, and it warrants the introduction and use of the other novel drugs. Several biochemical studies suggest that subgroups of children with pervasive developmental disorder show hyperserotonemia and increased endogenous opioid level as compared with controls. Psychopharmacological trials were conducted according to these findings(ex : fenfluramine, naltrexone), with mixed results till now. These and another drugs that have been used in children with pervasive developmental disorder and their effectiveness are reviewed.