Children and adolescents with cancer who receive chemotherapy and/or radiation treatments are at risk for malnutrition due to side effects such as nausea, vomiting, anorexia, and mouth sores. Malnutrition during treatment for childhood cancer increases the risk of infection, decreases tolerance to treatment, and even affects overall survival. A retrospective analysis of 79 children, adolescents, and young adults was conducted to evaluate nutritional screening at baseline and for the first 6 months of treatment. Interventions were also documented. Forty-nine participants had a positive screen for risk of malnutrition. In the patients with a positive screen, 78% had intervention within 24 hours of the identified risk for malnutrition. Thirty-five patients had a nutritional referral, which resulted in a full nutritional assessment and plan. Key independent variables were analyzed to determine if they were associated with an increased risk of malnutrition. In addition, individual risk factors were analyzed to determine their association with malnutrition. Future studies should find whether early intervention is effective in reversing the risk of malnutrition during treatment for childhood cancer.