A 55-year-old obese man was admitted to our hospital because of a severe morning headache. He snored and had recurrent episodes of sleep apnea that began 10 years earlier and had since become much worse. An overnight polysomnographic recording confirmed that he had sleep apnea syndrome, predominantly of the central type. The apneas were more frequent when he lay on his back (apnea index 54.5) than on his side (apnea index 1.2). He was treated with sleep position adjustment and nasal bi-level positive airway pressure, inspiratory positive airway pressure at 5 cmH2O and expiratory positive airway pressure at 2 cmH2O. His snoring, headache, and oxygen desaturation resolved. This case suggests that airway collapse may cause central apnea, and that nasal continuous positive airway pressure, and nasal bi-level positive airway pressure and adjustment of sleep position can be effective in some patients with central-type sleep apnea syndrome.