SUMMARY OBJECTIVE: The aim of our study was to determine the role of serum glucose–potassium ratio in predicting inhospital mortality in coronary care unit patients. METHODS: This study used data from the MORtality in CORonary Care Units in Turkey study, a national, observational, multicenter study that included all patients admitted to coronary care units between September 1, 2022, and September 30, 2022. Statistical analyses assessed the independent predictors of mortality. Two models were created. Model 1 included age, history of heart failure, chronic kidney disease, hypertension, diabetes mellitus, and coronary artery disease. Model 2 included glucose–potassium ratio in addition to these variables. Multivariate regression and receiver operating characteristic analysis were performed to compare Model 1 and Model 2 to identify if the glucose–potassium ratio is an independent predictor of inhospital mortality. RESULTS: In a study of 3,157 patients, the mortality rate was 4.3% (n=137). Age (p=0.002), female gender (p=0.004), mean blood pressure (p<0.001), serum creatinine (p<0.001), C-reactive protein (p=0.002), white blood cell (p=0.002), and glucose–potassium ratio (p<0.001) were identified as independent predictors of mortality through multivariate regression analysis. The receiver operating characteristic analysis indicated that Model 2 had a statistically higher area under the curve than Model 1 (area under the curve 0.842 vs area under the curve 0.835; p<0.001). A statistically significant correlation was found between the inhospital mortality and glucose–potassium ratio (OR 1.015, 95%CI 1.006–1.024, p<0.001). CONCLUSION: Our study showed that the glucose–potassium ratio may be a significant predictor of inhospital mortality in coronary care unit patients. OBJECTIVE glucosepotassium glucose potassium METHODS national observational 2022 30 created age failure disease hypertension mellitus variables RESULTS 3157 3 157 3,15 43 4 4.3 n=137. n137 n n=137 . 137 (n=137) p=0.002, p0002 p p=0.002 , 0 002 (p=0.002) p=0.004, p0004 p=0.004 004 (p=0.004) p<0.001, p0001 p<0.001 001 Creactive C reactive (p<0.001 0842 842 0.84 0.835 0835 835 p<0.001. p<0.001) OR 1015 015 1.015 95CI CI 95 10061024 006 024 1.006–1.024 CONCLUSION 202 315 15 3,1 4. n13 n=13 13 (n=137 p000 p=0.00 00 (p=0.002 (p=0.004 p<0.00 (p<0.00 084 84 0.8 0.83 083 83 101 01 1.01 9 1006102 02 1.006–1.02 20 31 3, n1 n=1 (n=13 p00 p=0.0 (p=0.00 p<0.0 (p<0.0 08 8 0. 10 1.0 100610 1.006–1.0 n= (n=1 p0 p=0. (p=0.0 p<0. (p<0. 1. 10061 1.006–1. (n= p=0 (p=0. p<0 (p<0 1006 1.006–1 (n p= (p=0 p< (p< 100 1.006– (p= (p 1.006 1.00