The term "isolated right thoracic isomerism" is used to describe a situation in which the anatomy of the bronchi, lung lobes, and pulmonary vessels on the left side is similar to that on the right side with no other cardiac or abdominal anomalies. We herein describe a patient who underwent surgical treatment for lung cancer in the left lung that was complicated by an isolated right thoracic isomerism. The unique anatomical and surgical problems in this thoracic anomaly are discussed.