To describe the short-term outcome of pediatric intensive care by quantifying overall functional morbidity and cognitive impairment, I developed the Pediatric Overall Performance Category (POPC) and the Pediatric Cerebral Performance Category (PCPC) scales, respectively. A total of 1469 subjects (1539 admissions) were admitted to the pediatric intensive care unit of Arkansas Children's Hospital from July 1989 through December 1990. Patients were assigned baseline POPC and PCPC scores derived from historical information and discharge scores at the time of discharge from the hospital (or from the pediatric intensive care unit for patients with multiple hospitalizations). Delta scores were calculated as the difference between the discharge scores and the baseline scores. The changes in POPC and PCPC scores were associated with several measures of morbidity (length of stay in the pediatric intensive care unit, total hospital charges, and discharge care needs) and with severity of illness (pediatric risk of mortality score) or severity of injury (pediatric trauma score) (p less than 0.0001). Interrater reliability was excellent (r = 0.88 to 0.96; p less than 0.001). The POPC and PCPC scales are apparently reliable and valid tools for assessing the outcome of pediatric intensive care.