In this article we investigate clinical specificity and sensitivity of cardiac troponin T and cardiac troponin I tests in the patients who were admitted to the hospital with suspected acute coronary syndrome. We investigated 87 patients: the clinical investigation was performed, electrocardiogram was recorded and concentrations of cardiac troponin T and troponin I were estimated. According to the recommendations of the manufacturers of troponin T and troponin I tests, threshold diagnostic troponin T concentration for myocardial infarction was considered > or =0.1 ng/ml and troponin I > or =1.0 ng/ml. Troponin T concentration was analyzed in 60 patients; the sensitivity of troponin T test in diagnosing acute myocardial infarction was 85%, and the specificity was 87.2%. Troponin I test was performed in 46 patients; the sensitivity of the test was 76% and the specificity was 76.2%. In case when both troponin T and I tests were performed, the sensitivity of troponin T was 100% and specificity was 78% and of troponin I - respectively 86% and 78%. According to the receiver operator characteristic analysis there was no significant difference between the general accuracy of troponin T and troponin I in distinguishing patients with and without acute myocardial infarction. According to the results of receiver operator characteristic analysis, the biggest clinical sensitivity and specificity were achieved when threshold myocardial infraction diagnostic concentration of troponin T was considered >0.04 ng/ml and of troponin I >0.69 ng/ml.