Aim:Hypercalcemia (HCM) is a common clinical problem characterized by a serum corrected calcium (cCa) level of >10.7 mg/dL. Primary hyperparathyroidism and malignancy are mostly (90%) involved in the etiology. In this study, we aimed to determine the relationship of cCa and phosphorus (P) levels, cCa/P ratio and gender with the etiology of HCM and one-week mortality.Methods:Records of HCM patients older than 18 years of age who were hospitalized between January 1, 2017 and December 31, 2018 were retrospectively reviewed. Age, gender, cCa and P levels, HCM etiology and one-week survival status of the patients were recorded. Subsequently, the patients were divided into two groups according to whether the etiology of HCM was benign or malignant. Then, the groups were compared statistically in terms of gender, biochemical values and one-week survival.Results:The median level of serum cCa was found to be significantly higher in males (p