The purpose of this study is to treat dysphagia in a newborn baby with cri du chat syndrome using an oral stimulation intervention and to examine its effects. The subject of this study was a baby born 2 weeks prematurely. Since birth, his oxygen saturation (SaO2) decreased while feeding, and he had difficulty with mouth feeding. Thus, an NG feeding tube was inserted, and dysphagia treatment was initiated on the sixth day after birth. A baseline phase and an intervention phase were performed using an AB design. The oral stimulation intervention was not performed in the baseline phase, as only nonnutritive sucking training using a rubber pacifier was used during the baseline phase. During the intervention phase, nonnutritive sucking training and oral stimulation intervention were simultaneously conducted. After the intervention period, daily oral milk intake and intake per feeding of the subject noticeably increased. The oxygen saturation while feeding rose over 90% on average, and the baby did not present with hypoxia. The oral stimulation intervention provided prior to feeding resulted in highly positive effects, including induced normal development of the baby, stimulation of his transition from the NG feeding tube to bottle feeding, increased oxygen saturation, and a shortened hospital stay.