Introduction/objective a myocardial infarction without coronary artery obstruction (MINOCA) is defined by universal acute myocardial infarction criteria with no obstructive coronary artery disease and no defined cause of the acute clinical presentation at angiography at that time. We are presenting an interesting case of hyperthyroidism as a potential cause of MINOCA. Case report the patient was admitted to the Clinic of Cardiology, Institute for Cardiovascular Disease Vojvodina under the suspicion of an inferior myocardial infarction with ST elevation. An emergency coronary angiogram was indicated and came back with normal coronary artery lumens. Echocardiography registered akinesia of the medioinferior and mediolateral wall with hypokinesia of the basal inferior wall accompanied by high levels of cardio specific enzymes. A working diagnosis of MINOCA was made and further diagnostic procedures were undertaken. Laboratory findings indicated hyperthyroidism, so the patient was put on suppressive therapy and low doses of beta blockers, nitrates an Ca antagonists. The hyperthyroidism most probably led to a coronary vasospasm, which is considered to have caused the MINOCA in our patient. Conclusion In younger patients, smokers who complain of chest pain early in the morning, hyperthyroidism should be considered to be a potential cause of MINOCA myocardial infarction.