BACKGROUND Unstable angina and non-ST elevation myocardial infarction (NSTEMI) are common acute coronary events. Homocysteine is a novel risk factor for coronary heart diseases. Together with the conventional risk factors, they may affect the outcome of non-ST coronary events. OBJECTIVE This study aims to determine the effect of clinical risk factors that are responsible for the occurrence of mortality, and the composite outcome of mortality, nonfatal myocardial infarction and serious rehospitalization within 6 months after the onset of non-ST acute coronary syndromes. METHODS A total of 124 Filipino patients were interviewed and tested for blood homocysteine levels and lipid profiles. Outcomes were assessed after 6 months. RESULTS Homocysteinemia (>16 micromol/l) is associated with increased mortality and composite outcomes (mortality, nonfatal reinfarction, and serious rehospitalization), even if adjusted for conventional risk factors. No association was detected for the conventional risk factors. Earlier acute coronary syndrome was found to be positively associated with mortality and the composite outcomes. Early stroke is associated with increased composite outcomes, whereas greater mortality and adverse outcomes were observed in NSTEMI compared with intermediate-risk unstable angina. CONCLUSIONS Increased homocysteine level is associated with mortality and serious nonfatal outcomes in patients with unstable angina and NSTEMI.