Single coronary artery (SCA) is defined as an isolated coronary artery that arises from a single coronary ostium and provides blood supply to the entire myocardium. At present, the absence of the right coronary artery is more common in SCA and the absence of the left coronary artery is rare. We report a case of a middle-aged man with congenital left coronary artery absence. The patient underwent coronary angiography after completing relevant examinations on admission, the results showed that the coronary artery blood supply was dominant in the right coronary artery; the right coronary artery was compensatively thickened and long, the part of the left coronary artery that functions as the anterior descending branch opens at the beginning of the right coronary artery and the blood vessels were small. The patient was given symptomatic supportive treatment during the hospitalization period and was discharged from the hospital. The patient’s condition was stable during the follow-up. This case demonstrates that although congenital left coronary artery absence is a rare disease, correct diagnosis, appropriate treatment and patient education play a vital role in the treatment of these patients.