Background:The clinical value of the Syntax score in patients with non-ST segment elevation myocardial infarction (NSTEMI) has been well established. The neutrophil-lymphocyte ratio (NLR), the platelet-lymphocyte ratio (PLR), the high sensitivity C-reactive protein (hsCRP)-albumin ratio (hsCAR), and systemic immune-inflammatory (SII) index are promising systemic inflammation (SI) biomarkers in coronary artery diseases. However, studies which compare the predicting value of these SI indicators with the Syntax score in NSTEMI patients are limited. Material and Methods: NSTEMI patients who underwent coronary angiography (CAG) in our department were retrospectively enrolled. Both univariable and multivariable logistic regression analyses were performed to evaluate the clinical value between SI biomarkers and Syntax score in these patients. The area under the receiver operating characteristic curve (ROC) was used to compare the clinical values of these parameters in predicting 6-month major cardiovascular events (MACE) and over-all mortality. Results: A total of 429 NSTEMI patients were finally enrolled in this study. The level of NLR, PLR, as well as hsCAR, and SII in patients with high Syntax scores, are significantly higher than patients with the low Syntax score. Multivariable logistic regression analysis demonstrated that all of the SI indicators but not the Syntax score were the independent risk factors of 6-month MACE in NSTEMI patients. ROC showed that all of the SI indicators had better predictive value than the Syntax score in these patients (0.637, 0.592, 0.631, 0.590, 0.559, respectively) in predicting MACE and similar predictive value in over-all mortality (0.530, 0.524, 0.761, 0.553, 0.620, respectively). Conclusion: Novel SI biomarkers including NLR, PLR, hsCAR, and SII have better predictive value in MACE and similar predictive value in over-all mortality compared with Syntax score in NSTEMI patients.