Objective To evaluate the early diagnostic value of ischemia modified albumin (IMA) for non-ST-segment elevation acute coronary syndromes (NSTEACS). Methods The study group consisted of 177 patients with suspected NSTEACS whose blood was collected within six hours after the onset of chest pain to determine cardiac troponin I (cTnI), and IMA was determined through the albumin cobalt binding (ACB) test. After standardized diagnosis and treatment and GRACE risk score, the patients then were divided into three groups according to the final diagnosis: the NSTEMI (non-ST-segment elevation myocardial infarction) group (n=34), the UA (unstable angina pectoris) group (n=56) and the NICP (non-ischemia chest pain) group (n=87). Meanwhile, 58 people taking the routine examination in the same hospital at that time were randomly selected as the control group. With the results of IMA, ROC curve analysis was used to determine the optimal cutoff of this assay for identifying patients with NSTEACS from those with NICP. Results of IMA, ECG and cTnI were correlated with final diagnosis, and their diagnostic sensitivity and specificity were evaluated for NSTEACS. Results The IMA concentration in the serum showed no significant difference between the NSTEMI group and the UA group, whereas there were significant differences between the former two groups and the NICP group. The sensitivity and specificity at a cutoff point 67.49 U/mL were 91.1% and 86.2%, respectively when the ROC curve area was 0.950. The correlation between the IMA concentration and GRACE risk score was negative. Conclusion IMA is an early sensitive indicator for NSTEACS and a useful predictor of prognosis.