This paper reviews the published literature on the use of selective serotonin reuptake inhibitors (SSRIs) for the treatment of symptoms associated with autistic disorder and other pervasive developmental disorders (PDDs) in both children and adults. To date, placebocontrolled studies of SSRIs have involved only fluvoxamine (in children and adults) and fluoxetine (in children). Open-label and retrospective studies of all other SSRIs in PDDs have also been published that suggest effectiveness. Despite these positive reports, there continues to be questions about the tolerability and appropriate dosing of SSRIs in children with PDDs. Because of the limited number of placebo-controlled studies, definitive conclusions about the role SSRIs should play in the clinical treatment of children with PDDs cannot be drawn. Larger, placebo-controlled studies of SSRIs are needed to guide clinical treatment.