There is little information on the treatment of comorbid bipolar disorder and pervasive developmental disorder (PDD) in youth. This paper will provide a review of the literature on appropriate psychopharmacological treatment strategies for bipolar disorder and PDD in children and adolescents and make recommendations for psychopharmacological treatment and monitoring of the comorbid presentation of these two disorders. The purpose of this paper is to provide clinicians with evidence-based research findings of treatment strategies used by the experts in the field of pediatric bipolar disorder and PDD. Sources for the study have been published reviews and research articles. Studies addressing the complex treatment issues of comorbid pediatric bipolar disorder and PDD are limited. Research studies have demonstrated improvement in psychiatric functioning of children and adolescents with bipolar disorder and PDDs who took atypical antipsychotics and mood stabilizers. Children with bipolar disorder have benefited the most from the combination of a mood stabilizer plus an antipsychotic. However, there are no studies looking at combined medication treatments for PDD. Children who manifest both disorders could possibly benefit from this combination. While selective serotonin reuptake and tricyclic antidepressants inhibitors have demonstrated improvement in PDD symptoms, they should be used with caution in children who have comorbid bipolar symptoms as they can cause agitation, mania or, in a limited number of cases, serotonin reuptake inhibitors have increased suicidal behavior. More extensive, long-term research is needed to find better treatments to improve quality of life and outcomes in this difficulty to treat population.