The 5p deletion syndrome (5p-, Cri-du-chat syndrome, CdCS) is a genetic disorder which results from a partial deletion of the short arm of chromosome 5. It was first described by Lejeune et al. in 1963. The incidence ranges from 1:15 000 to 1:50 000 live births. The 5p- is usually diagnosed in the first days of life because of the characteristic monotonous high pitched cat-like cry and relatively constant dysmorphic features. Other symptoms often present in the neonatal period include low birth weight, muscle hypotonia, asphyxia and feeding difficulties due to impaired suction and swallowing, which may all lead to failure to thrive. Organ malformations, with various larynx abnormalities, although not very frequent, can also be present. Symptoms that are prevalent in later life include severe motor delay and intellectual disability with significant speech impairment, as well as behavioral problems. The case report presents a female infant in her 5th month of life in whom, despite the typical symptoms of 5p-, stridor and episodes of choking were the main problems. Laryngotracheal endoscopy revealed the type I laryngeal cleft. Genetic analysis confirmed the diagnose of 5p- syndrome. The presented case shows that it is critically important to perform a further investigation and refer a child with laryngological problems coexisting with dysmorphic features to a clinical geneticist.