Background: Despite effective interventional treatments, the mortality of acute ST-segment elevation myocardial infarction (STEMI) is still high. Several mortality predictors are known in STEMI. Platelet-tohemoglobin ratio (PHR) is a recently used mortality parameter in cardiac or non-cardiac diseases. We aim to investigate the relationship of PHR with in-hospital mortality in patients with STEMI.Methods: Eight hundred eighty-four patients were included in the study. All of them underwent coronary intervention due to STEMI. Demographic characteristics, laboratory, electrocardiographic and echocardiographic parameters were analyzed from hospital records. A cut-off value for PHR was determined using receiver operating characteristic (ROC) curve analysis. Then, patients were divided into two groups PHR < 1.99 and PHR ≥ 1.99. The data of both groups were compared.Results: The median age of the study population was 64 (54-75). Of these 633 (71.6 %) were male and 251 (28.4 %) were female. All cause mortality of the study population was 9.7% (n=86). In multivariable logistic regression analysis, PHR was independently associated with a significantly increased risk of in-hospital mortality for STEMI (