The Child Behavior Checklist (CBCL) parent-report school-age form, a broad instrument widely used to evaluate youth's emotional and behavioral functioning, includes seven sleep-related items. These items are not an official subscale of the CBCL, but researchers have used them as a measure of general sleep problems. The primary objective of the present study was to evaluate the construct validity of the CBCL sleep items with a validated measure of sleep disturbance, the Patient-Reported Outcomes Measurement Information System Parent Proxy Short Form-Sleep Disturbance 4a (PSD4a). To do so, we used coadministered data on the two measures from 953 participants ages 5-18 years in the National Institutes of Health Environmental influences on Child Health Outcomes research program. Exploratory factor analysis (EFA) revealed two CBCL items were strictly jointly unidimensional with the PSD4a. To help prevent floor effects, we conducted further analyses that revealed three additional CBCL items could be included as an ad hoc measure of sleep disturbance. However, the PSD4a remains a psychometrically superior measure of child sleep disturbance. Researchers using these CBCL items to measure child sleep disturbance should account for these psychometric issues in their analysis and/or interpretation. (PsycInfo Database Record (c) 2023 APA, all rights reserved).