The aim of the study was to analyze the prognostic implications of 3 myocardial necrosis markers measured at admission in short-term observation of patients with suspected acute coronary syndrome. The study group consisted of 336 consecutive patients whose concentration of cardiac troponin I, creatine kinase-MB fraction, and myoglobin were measured at admission. All patients referred due to chest pain and suspected acute coronary syndrome and were followed up for 30 days. The patients who died had statistically higher concentration of cardiac troponin I (8.7 +/- 17.2 vs 0.9 +/- 3.2 ng/mL; P = .0006), myoglobin (215.2 +/- 181.5 vs 109.7 +/- 151.5 ng/mL; P = .003), and creatine kinase-MB (21.9 +/- 30.7 vs 8.8 +/- 25.9 ng/mL; P = .005), compared to patients who stayed alive. There was statistically significant increase in 30-day all-cause mortality with increasing numbers of positive markers-0.6% for patients with nonpositive marker, 3.4% for patients with 1 positive marker, and 11.5% for patients with at least 2 positive markers (P = .001 for trend).