Background: Nutrition plays a deciding role and a key factor in children with cancer and can influence their outcome. It is essential for appropriate growth and development and a critical component in the optimization of clinical outcomes. Objective: This study aimed to improve the nutritional status of children and evaluate the impact of nutritional counseling and support for these children with cancer. Patients and Methods: This interventional study was performed in the Oncology Pediatric Department, at the Zagazig University Children's Hospital for the period from February to August 2021. The study included 54 pediatric cancer patients who will start chemotherapy. Results: there were no statistically significant differences between the studied groups according to the Patient-Generated Subjective Global Assessment (PG-SGA) scale at a baseline or 45^th day but there was a statistically significant increase in the frequency of type A among the interventional group and a statistically significant increase in C and D type among the control group at 90^th day. The interventional group showed a statistically significant increase in type A at 90^th day compared to baseline. There was a statistically significant increase in the mean physical, social, functional domain, anorexia/cachexia subscale (A/CS), and total FAACT scores among the interventional group compared to the control group. Conclusion: nutritional intervention is mandatory for cancer patients to prevent cachexia and improve their physical and social state. Functional assessment of anorexia/cachexia therapy (FAACT) scale and anorexia/cachexia subscale (A/CS) have good content validity and can be used for characterizing the effect of nutritional intervention and treatment of anorexia symptoms and/or anorexia-related concerns in patients with cancer.