An abnormal shadow was detected in a 15-year-old male adolescent by routine chest radiography during a school medical examination. Further detailed examination demonstrated stage IA primary lung adenocarcinoma in the right inferior lobe. The patient then underwent surgery. The right inferior lobe was resected, and the mediastinal lymph node was dissected by the microthoracoscopic one-port method. Thoracoscopic surgery for stage IA primary adult lung cancer has been established. However, no report has been published on thoracoscopic surgery, particularly the one-port method, for rare primary lung cancer in an adolescent, as demonstrated in this case.