The psychometric properties and factor structure of a widely used screening measure for behavioral and emotional dysfunction, the Pediatric Symptom Checklist (PSC), was extended to a population of chronically ill children. Parents of 404 children ranging from 6 to 17 years of age and diagnosed with either insulin-dependent diabetes mellitus (IDDM) or sickle cell disease (SCD) completed the PSC while waiting for a routine medical appointment. The measure's internal consistency was found to be high, Cronbach's alpha = .89, and test-retest reliability across 4 months was observed to be acceptable, r = .77. A principal components analysis with an oblique (promax) rotation yielded a four-factor solution with factors that included items representative of internalizing, externalizing, attention, and chronic illness-related problems, respectively. Cronbach alpha estimates ranged from .78 to .83 for the first three factors but was lower for the chronic illness-related problems factor (Cronbach's alpha = .60). A three-factor solution and reliability estimates were recomputed without the chronic illness items that yielded the same reliability estimates for each of the three factors and for the full scale. The three-factor solution was also found to be similar to a published factor structure obtained with a primary care sample, rc = .90-.91. The findings lend support to extending the PSC's clinical utility to tertiary care pediatric settings. Further research is recommended with a broader range of chronic illness groups to increase generalizability. Copyright © 2005 by Lippincott Williams & Wilkins, Inc.