The objective of our study is to estimate the radiation exposure to pediatric patients with sarcoma getting required (or highly recommended) ionizing radiation scans during initial chemotherapy and to determine how often distant progressive disease was discovered. Data from the last 25 years from the Children's Oncology Group open phase III protocols were reviewed for the most common pediatric sarcomas: osteosarcoma, Ewing's sarcoma, and rhabdomyosarcoma. The number of required/recommended ionizing radiation scans, including chest radiographs, chest computed tomography, positron emission tomography scans, and bone scans during induction, consolidation, and maintenance chemotherapy, were recorded and the total radiation dose per patient was calculated. In addition, the number of patients who were removed from protocol during chemotherapy because of new or distant progressive disease was documented. In our analysis of 5845 patients, the average pediatric patient with sarcoma on protocol was exposed to an ionizing radiation dose of 37.1 mGy, equivalent to the lifetime dose of nuclear power plant workers, whereas the progression of disease was detected at most in 5.4% of the patients. Our study is meant to inform pediatric oncologists more precisely of the actual risks and benefits of mandated surveillance scans during chemotherapy in patients with sarcoma.