After participating in this educational activity, the physician should be better able to1. Prescribe the appropriate psychotropic medication to treat symptoms of ASD.2. Identify the side effects of the psychotropic medications used to treat ASD.Autism spectrum disorders (ASDs) are characterized by core deficits in social communication and language, and restrictive and repetitive behaviors that cause significant functional impairment and distress for affected individuals and their caregivers. The increasing prevalence of ASD, most recently estimated as 1 in 88 children, presents an ever-increasing burden on families, schools, medical systems, and society at large. Individuals with ASD commonly present for treatment of associated emotional and behavioral disturbances that include anxiety, symptoms of ADHD, compulsions and other repetitive behaviors, mood lability, irritability, aggression, and sleep disturbance. Psychotropic medications are widely utilized in alleviating these symptoms, though rigorous clinical trials in ASD are lacking for most areas of impairment. Strong evidence from randomized, placebo-controlled trials supports the use of atypical antipsychotics, particularly risperidone and aripiprazole, for managing severe irritability and aggression in ASD. Serotonin reuptake inhibitors are commonly used to treat anxiety and compulsions, though reports of efficacy in the literature are mixed, and behavioral side effects in children are common. Minimal evidence supports the utility of anticonvulsants and traditional mood stabilizers in managing mood lability and aggression. Stimulant and nonstimulant ADHD medications can be effective for reducing hyperactivity, inattention, and impulsivity, though to a lesser degree than in ADHD populations without ASD and with greater risk of adverse effects. Psychopharmacological interventions in development for core symptoms of autism include those that target the glutamatergic and GABAergic neurotransmitter systems and the neuropeptide oxytocin. Further research is needed to establish evidence-based interventions in ASD populations.