A series of 14 children and adolescents (ages 9–17 years, 10 males) were treated with risperidone for pervasive developmental disorder. The rationale for using an atypical neuroleptic agent is based on its ability to target both positive and negative symptoms of schizophrenia. It was postulated that symptoms similar to the positive and negative symptoms of schizophrenia may be observed in the pervasive developmental disorders and might respond favorably to risperidone. Twelve of the 14 youths had been treated previously with several psychotropic drugs, often concurrently. Risperidone was initiated at a starting dose of 0.25 mg twice daily and increased in 0.25 mg/day increments every 5–7 days. Optimal dosages ranged from 0.75 to 1.5 mg daily in divided doses. Thirteen of the 14 youths appeared to benefit from risperidone. Improvement in functionality on the Children's Global Assessment Scale was demonstrated in 13 of 14 cases. Disruptive behaviors, when present, markedly decreased on risperidone. Ten patients showed a marked reduction in agitation and anxiety. Social awareness improved markedly in 10 patients, moderately in 3, and only slightly in 1. All but 1 patient demonstrated a lessening in obsessional behaviors. Effects on attention were uniformly positive. Side effects were minimal at the dosages used in this study; 5 patients had initial sedation. Neither extrapyramidal side effects nor agitation was observed in any case. Ten of 14 youths could be managed with risperidone monotherapy. During the follow-up period (mean 7 months), none of the patients experienced a major relapse while taking risperidone. Positive and negative symptoms, as typically characterized in schizophrenia, were both found to improve equally well with risperidone treatment. Based on these findings, a prospective clinical trial with a randomized controlled design is warranted.