Although thoracic trauma is frequently accompanied by myocardial injury; this later is often oversighted at early stages of trauma and misdiagnosed by the time complications are present. Myocardial abnormalities have been attributed to a reduction of cardiac flow. Nitroglycerin and isosorbide dinitrate, both agents with a known vasodilator effect on coronary arteries, might improve myocardial ischemic resulting from traumatic contusion. In order to compare safety and efficacy between two nitrates and placebo on myocardial contusion resulting from thoracic trauma, we carried out a comparative, prospective, single blind study. Subjects were randomly allocated to one of the following 3 groups: a) transdermal nitroglycerin, b) isosorbide dinitrate and c) placebo. Medication was dispensed for five days. Major endpoint were electrocardiographic abnormalities at entry and their final modifications. Other were severity injury score and myocardial enzyme levels. Twelve patients were included in each group. Four measured enzymes were high at entry, but MB fraction in the nitroglycerin group showed the most rapid normalization. Creatine phosphokinase and lactic dehydrogenase significantly correlated with severity injury index, but not MB fraction. Electrocardiographic normalization was mainly observed in the nitroglycerin group. Transdermal nitroglycerin systems demonstrated to be effective on recovering from electrocardiographic abnormalities resulting of myocardial contusion.