Background: Misdiagnosis of angina pectoris is not uncommon in athletes. Physicians can fail to make a correct clinical diagnosis if they don’t have the skills and experience needed to recognize this disease. Case Report: This case report describes an exertional angina misdiagnosis due to a severe coronary artery disease in a 50-year-old male athlete initially examined by both a general practitioner and a cardiologist. The athlete subsequently underwent physical examination in a sports cardiology medicine center where diagnosis of angina pectoris caused by severe mono-vessel coronary artery disease was made, requiring an angioplasty with stenting. Conclusions: Although most of the severe symptoms in a heart attack are hard to miss, sometimes in athletes angina pectoris is not readily recognized. However, this is dangerous and can lead to the sudden death of the athlete. Diagnosis must be timely and accurate, in order for the patient to receive the best prognosis.