Adrenocortical carcinoma (ACC) in childhood is rare: in 2002, only three new cases were reported in Japan. Although there is no established therapeutic management system, margin-free complete surgical excision of the tumor is very important to a satisfactory outcome. We report a case of ACC with bilateral pulmonary metastasis in a 10-year-old boy. Preoperative chest computed tomography (CT) showed pulmonary metastasis with near-water density. The patient was treated successfully with complete surgical resection of the primary tumor and adjuvant chemotherapy, including mitotane. After bilateral lung surgery for the metastatic lesions, the plasma dehydroepiandrosterone sulfate level became negative.