Postoperative dietary control and surgical procedures are important for minimizing complications after a palatoplasty because the palate is always exposed to stresses by various movements associated with eating. Currently, we provide fluid foods (food paste, liquid food, and soft food) to postpalatoplasty patients. However, nutritional inadequacies associated with fluid food necessitate the need to develop a new food specifically for postpalatoplasty patients. Although evaluating the influence of a palatoplasty on eating function is important for the development of a new diet, no data have been published on this topic. Thus, to evaluate the influence of a palatoplasty on eating function, we analyzed postoperative changes in the eating condition of cleft palate patients. We performed a retrospective study. All participants had undergone surgery for a cleft palate at our hospital. Nurses recorded the amount of food that patients consumed as a ratio of the whole meal, and we extracted data on the food type and the amount consumed at each meal from their medical records. After the ratio was expressed as a percentage of the whole meal (eating rate), we calculated the mean value of the percentage of the subject group and examined chronological changes. The eating rate was very low on postoperative day 1, it improved over time and was constant on postoperative day 7. From this result, we concluded that palatoplasty greatly influences the eating function of patients, and the influence lasts for at least a week after surgery.