No widely accepted method exists to evaluate pediatric hematology oncology patients for the risk of venous thromboembolism (VTE) and the need for prophylaxis. The use of a VTE risk-assessment tool and standardized guidelines for prophylaxis could increase the use of appropriate prophylaxis and reduce the number of VTEs in patients, thereby decreasing morbidity, mortality, hospitalization, and cost. The purpose of this project was to implement and assess the compliance of a pediatric-specific VTE risk-assessment tool in hospitalized pediatric, adolescent, and young adult hematology oncology patients. From the 114 pediatric, adolescent, and young adult patients requiring assessment, 91 (80%) VTE assessments were completed and 87 (96%) were completed accurately. Eighty percent of the at-risk patients were ordered VTE prophylaxis. The use of a VTE risk-assessment tool in pediatric hematology oncology patients is a feasible way to assess patients for their risk of developing a VTE.