Introduction  NPO Japan Heart opened a children’s medical center in Cambodia in 2018 to treat pediatric cancer. In many public hospitals in Cambodia, patients’ meals must be prepared by their families with little knowledge about hygiene and nutrition, so patients may not always receive sufficient nutrition for their treatment. We considered a hygienic and nutritious diet essential for effective pediatric cancer treatment.  Therefore, the “Japan Heart Children’s Medical Center Meal Project” was launched. The objectives of this study were as follows; (1) to describe that patients receive hygienic and nutritious meals during their hospitalization and after discharge, (2) to measure the effects of providing hospital meals and nutrition education by Cambodian staff who are not qualified dietitians, and to clarify the changes in the nutritional status of pediatric cancer patients as a result of these activities.Methods  The target group was pediatric cancer patients and their families.  Japanese dietitians and chefs conducted study sessions, created menu standards based on the Minimum Dietary Diversity (MDD) , and trained local staff to provide meals and nutrition education.   To provide hospital meals, local staff conducted hygiene management, prepared menus based on standards, and measured eating rates. They also provided nutrition education to the patients and their families, and connected survey before and after education. Nutrition assessment was conducted based on WHO Growth Chart BMI for age by measuring height and weight.Results  The MDD achievement rate for the menu increased from 72% to 100% (after intervention 1week-2 week (January, 2020)), and the eating rate increased from 45.9% to a maximum of 80.5% (April, 2020-January, 2022). Surveys before and after nutrition education showed that 89.1% of patient families improved their knowledge and awareness. Height and weight were assessed by BMI, and the percentage of patients with ≤−2SD decreased from 28.1% at admission to 15.9% at discharge.  Conclusions  In Cambodia where there is no dietitian system, it is important to do activities with contents that is feasible for local staff who have never studied nutrition.  In order to further support treatment from the nutritional aspect, it is desirable to develop nutritional human resources in Cambodia.