Objective:White blood cell (WBC) count to mean platelet volume (MPV) ratio (WMR) is associated with major adverse cardiovascular events in patients with non-ST elevation acute coronary syndrome (NSTEMI). We aimed to compare WMR between NSTEMI patients and matched-controls and to evaluate its predictive value on SYNTAX score.Methods:Total 175 patients with NSTEMI and 160 age and co-morbidity matched subjects were recruited in our study. WMR was compared between the patient and control groups. The patient group was further subdivided into 3 tertiles according to SYNTAX scores as follows: low SYNTAX score tertile (score ≤22, 141 patients); intermediate SYNTAX score tertile (score between 23 and 32, 20 patients); and, high SYNTAX score tertile (score ≥33, 14 patients). WMR was further assessed among the tertiles.Results:WMR was significantly greater in the patient group compared to the control group (p<0,001). WMR among low, intermediate and high score tertiles were calculated to be 890±26, 1090±042 and 1500±65, respectively (p <0,001). In receiver operating characteristics (ROC) analysis, WMR >960 predicted a SYNTAX score ≥23 with 80.6% sensitivity and 67.6% specificity (AUC: 0.756; 95% CI: 0.685 - 0.818; p <0.0001) and a WMR >1360 predicted a SYNTAX score ≥33 with 71.4% sensitivity and 93% specificity (AUC: 0.840; 95%CI: 0.777 - 0.892; p <0.0001).Conclusions:WMR value was significantly elevated in NSTEMI patients, compared to controls. Higher WMR was associated with greater SYNTAX score in patients with NSTEMI. WMR may be used to predict severity of the CAD and to implement risk stratification in patients with NSTEMI.