Left internal thoracic artery (LITA) has increased importance and common use in coronary bypass grafting because of long-term better patency rate and improvement in both the duration and quality of survival of patients. LITA is a branch of the first part of the subclavian artery. We report a case in which the LITA originated from the second left intercostal artery. A 71-year-old man with a history of angina pectoris for 1 month was admitted to the hospital because of progressive increase in anginal symptoms. During the operation, it was noted that the LITA originated from the second intercostal artery. LITA used as a free graft. LITA was anastomosed to the left anterior descending coronary artery. He was free of symptoms 4 weeks after operation. To our knowledge, this is the first reported case of the LITA originating from the second intercostal artery.