Observational data suggest pediatric intensive care unit-related sleep and circadian disruption (PICU-SCD) affects many critically ill children. Multicenter trials exploring PICU-SCD have been impractical because measuring sleep in this setting is challenging. This study validates a questionnaire for caregivers to describe children's sleep in the PICU. This prospective, multicenter, case-control study enrolled caregivers of children in 4 PICUs or in a hospital-based sleep laboratory (controls). Survey items were compiled from validated adult ICU and pediatric in- and outpatient sleep questionnaires. Control responses were compared to polysomnography to determine accuracy. A score was calculated by summing the level of disruption of sleep timing, duration, efficiency, quality, and daytime sleepiness and irritability. In responses from 152 PICU and 61 sleep laboratory caregivers, sleep survey items had acceptable internal reliability (α = 0.75) and reproducibility on retest surveys (interclass correlation coefficient > 0.600). Caregivers could not assess sleep of sedated children. Factor analysis identified 3 subscales of PICU-SCD. Control parents had good agreement with polysomnography sleep onset time (κ = 0.823) and sleep onset latency (κ = 0.707). There was a strong correlation between sleep scores derived by parental reporting to those by polysomnography (r = .844, P < .001). Scores had a linear association with caregiver-reported child sleep quality. There were no site-specific differences in sleep quality. Nearly all respondents found the survey easy to understand and of appropriate length. The Survey of Sleep Quality in the Pediatric Intensive Care Unit provides a reliable, accurate description of inpatient sleep disruption in nonsedated children, generalizable across PICUs. It offers practical means to quantify PICU-SCD daily in future investigations. Hassinger AB, Mody K, Gomez R, etal. Validation of the Survey of Sleep Quality in the Pediatric Intensive Care Unit (SSqPICU). J Clin Sleep Med. 2024;20(8):1251-1258.