STUDY OBJECTIVES: Data on sleep disorders in Cri du Chat (CdC) syndrome are limited; this study examines their prevalence, clinical features, and age-related patterns in pediatric patients. METHODS: Caregivers of children with CdC syndrome (<18 years), recruited through the Italian CdC Children's Association, completed a structured survey. The questionnaire included four validated sleep assessment tools: the Child's Sleep Habits Questionnaire (CSHQ), the Pediatric Insomnia Severity Index (PISI), the Epworth Sleepiness Scale for Children and Adolescents (ESS-CHAD), and the Sleep Questionnaire for Children with Severe Psychomotor Impairment (SNAKE). Analyses were conducted on the overall sample and stratified by age groups (0-6, 7-12, and 13-17 years). RESULTS: Fifty-one participants were included (median age 10 years; IQR 5-14 years). Pathological CSHQ scores were observed in all participants. Younger children exhibited significantly greater insomnia severity on the PISI and higher SNAKE scores for sleep maintenance disorders and daytime sleepiness (p < 0.05). Daytime somnolence assessed by ESS-CHAD was generally mild and showed a decreasing trend with increasing age. Severe intellectual disability was significantly associated with sleep-related arousal and breathing disorders (p = 0.016) and with daytime sleepiness (p = 0.032). Overall, 51% of patients had received pharmacological treatment at least once, with melatonin being the most frequently used medication and reported as effective in 68% of treated cases. CONCLUSIONS: Sleep disturbances are highly prevalent across all pediatric age groups in CdC syndrome and present distinct age-related patterns. Routine screening using standardized questionnaires may facilitate early identification and tailored interventions. CLINICAL TRIAL: The study was approved by the Ethical Committee (Comitato Etico Territoriale Lazio Area 1; study number 7980, Prot. 0481/2025). STATEMENT OF SIGNIFICANCE: Sleep disturbances represent an underrecognized but clinically relevant aspect of Cri du Chat syndrome. This study provides one of the first systematic characterizations of sleep problems across pediatric age groups in this rare neurodevelopmental condition, highlighting age-related patterns and associations with cognitive severity. By integrating multiple caregiver-reported sleep measures, the findings underscore the pervasive impact of sleep disturbances on daily functioning and well-being. The results emphasize the need for routine sleep assessment in clinical practice and support the development of tailored, age-specific management strategies. Future research should focus on longitudinal trajectories, objective sleep measures, and optimized therapeutic approaches to improve outcomes in this population.