Features useful in distinguishing children with pervasive developmental disorder (PDD) from those with autism or language disorder were developed from a retrospective chart review using groups of children with PDD-NOS and MA- and sex-matched autistic and language-disordered groups. Charts were reviewed using a list of 80 items compiled from various sources. Items that had adequate interrater reliability and significantly discriminated the PDD-NOS cases from the language-disordered or autistic cases were then evaluated using a second set of cases and signal detection methods. Fewer items significantly discriminated cases with autism from those with PDD-NOS as compared to cases with language disorder. Clinical implications are discussed.