Background: Cri du Chat syndrome (CdC) is a rare disease caused by the deletion on the short arm of the chromosome 5, with an incidence of 1:15,000 to 1:50,000 live-born infants. No study at international level has assessed the costs, Quality of Life (QoL) and Disability through standardized quantitative tools. The aim is to estimate economic costs related to CdC from a societal perspective, to assess the QoL and Disability in patients with CdC along with their caregivers in Italy. Methods: A cross-sectional study of patients with Cri du Chat in Italy was carried out. A cost of illness approach from a societal perspective was used to estimate cost, and a micro-costing method was adopted. The QoL was measured with EuroQol 5-domain (EQ-5D) questionnaire and Disability by using World Health Organization Disability Assessment Schedule 36 item (WHODAS 2.0). Results: A total of 76 questionnaires were collected from caregivers taking care of 40 adult patients and 36 minor patients. All patients need a carer and the principal caregiver is commonly informal carer or a family member (93%). The EQ-5D VAS score for patients is 65.5 (SD = 22.4) out of 100; while the most important compromised areas of QoL are usual activities and self-care. The overall WHODAS 2.0 score is 65% (0 = no disability; 100 = full disability). The average annual cost of a patient with Cri du Chat in our population is €87,856.24; the main cost item of patients with Cri du Chat syndrome is informal care (i.e., €76,981.69 yearly) since it constitutes the 87% of total costs. Results highlight the burden of CdC in terms of its impact on QoL and Disability for patients and caregivers in Italy, with a score much lower than that of general population. The disease is associated with considerable costs of informal care. Conclusions: Cri du Chat syndrome was found to be linked with a significant socioeconomic impact which is dominated by direct non-healthcare informal costs.