Congenital central hypoventilation syndrome (CCHS) is a rare disease characterized by hypoventilation mainly during sleep, but hypoventilation can be present during both wakefulness and sleep in severe cases. There is an abnormality in the chemical regulation of the respiratory center in the medulla, which results in insufficient ventilatory responses to hypercapnia and hypoxemia, resulting in a state of severe hypoventilation that persists without dyspnea. The paired-like homeobox 2B (PHOX2B) gene is the disease-defining gene for CCHS. CCHS is frequently accompanied by Hirschsprung disease, neuroblastoma, and dysregulation of the autonomic nervous system. The basic treatment is to manage breathing, including during sleep, and in severe cases, when awake. Treatment options, such as diaphragm pacing, are now available for hypoventilation during wakefulness, which had been difficult to treat in the past in Japan. If respiratory management and other complications are properly managed, the prognosis is good. To further improve prognosis, it is important to continue to study more appropriate respiratory management and to address new issues such as the transition of pediatric patients to the adult care system.