Pulmonary adenofibroma is a rare biphasic tumor that contains epithelial and stromal components. We report a case of pulmonary adenofibroma in which the tumor was resected by thoracoscopic surgery and the diagnosis was established by histopathology. A 59-year-old woman with a past medical history of pyelonephritis visited our hospital for evaluation of an abnormal opacity on a plain chest x-ray during a comprehensive medical examination. A follow-up chest x-ray showed enlargement of the lesion, and the patient was referred to our department for further management. Chest computed tomography revealed a well-circumscribed nodule measuring 1.4 cm in diameter in the upper lobe of the left lung. The chest imaging findings suggested a benign tumor, but because of evidence of lesion enlargement and elevated serum carcinoembryonic antigen levels, we performed wide wedge resection of the left upper lobe by video-assisted thoracoscopic surgery, for diagnosis and treatment. The resected specimen was submitted for rapid pathological diagnosis during the operation, and a benign tumor, possibly sclerosing pneumocytoma, was suspected. Therefore, we completed the operation with wide wedge resection. The final histopathological diagnosis was pulmonary adenofibroma. The patient had an uneventful postoperative course, and at this writing, 6 months postoperatively, there has been no evidence of tumor recurrence. We have reported this case of pulmonary adenofibroma because the tumor is rare, has not yet been well-characterized, and has an unclear prognosis. Collection of data from a larger number of patients is necessary.