A 71-year-old man was found to have growing nodules in his right lung, and an anterior mediastinal tumor. A positron-emission tomography (PET) scan demonstrated accumulation in one of the nodules and in the anterior mediastinal tumor. The rapid intraoperative pathological diagnosis was adenocarcinoma from the lung nodules and low grade malignancy from an anterior mediastinal tumor. Right upper lobectomy and lower partial lobectomy with mediastinal tumor resection was performed. Postoperative pathological examination revealed the coexistence of lung cancer and a typical carcinoid of the thymus. To the best of our knowledge, we report the first case of thymic carcinoid accompanied with adenocarcinoma of the lung.