No studies have analyzed agreement between mother, father, and teacher ratings of academic, cognitive, and handwriting problems in school-age children and compared these with objective achievement, IQ, and writing scores. The sample comprised 503 children with autism and/or ADHD 6-16 years rated by mothers, fathers, and teachers on the Pediatric Behavior Scale and administered IQ, achievement, and graphomotor tests. Interrater agreement and correlations were all significant, and mean informant ratings for academic, cognitive, and writing problems were similar (between "sometimes" and "sometimes/often" a problem). However, mother ratings were higher than father and teacher ratings, and mother-father agreement was better than mother-teacher and father-teacher agreement. Correlations between ratings and test scores were significant, but agreement on children identified with and without problems was poor. Informants identified more children as having problems than did test scores. Information from multiple sources requires integration by experienced, well-trained school psychologists and other educational and clinical professionals and can provide useful educational and diagnostic information to aid in targeted intervention.