A study has been undertaken in a unit of pediatric gastroenterology and nutrition. The unit also deals with general pediatric emergencies. The purpose of this study was to calculate the cost of hospitalization and the distribution of the cost between the different components: personnel expenses (medical and non-medical staff), cost of products used (enteral and parenteral nutrition included), cost of medicotechnical intervention. The study was carried out over a period of 28 days and included 117 hospitalized children. Only the expenses directly linked to the patient's care were taken into account. The exact time spent with each patient by every category of staff, the quantity of products and the treatment given had to be carefully recorded. The results reveal the share of the cost which goes to non-medical staff (about 60%), except when pathological cases need frequent and detailed investigations. Once the budget has been determined, department heads are required to play administrative role and this study underlines the process of cost build-up and thus enables a selective intervention in one sector or another of hospital expenses.