Aim:Metabolic syndrome(MetS) is associated with chronic inflammation,immune function and nutritional status. The C-reactive protein-albumin-lymphocyte(CALLY) index is a new index that may have prognostic value in various cancers and cardiovascular diseases.Magnesium(Mg) affects the functioning of many enzymes involved in glucose metabolism.Calcium(Ca) plays a key role in hypertension and obesity.This study aimed to investigate the relationship between MetS and serum Mg/Ca ratio and CALLY index. Methods:This study was done retrospectively on individuals over 18 years of age who applied to the Unit No.56 Family Medicine in Karaman Center between April 1,2023 and April 1,2025.Age,gender,smoking,blood pressure values,height,weight and waist circumference were evaluated.In addition,laboratory results such as fasting serum Mg,Ca,Hemoglobin A1c,low-density lipoprotein,high-density lipoprotein,total cholesterol,triglyceride,blood glucose,insulin,albumin,CRP levels and lymphocyte count were evaluated.Body mass index(BMI),Homeostasis Model Assessment(HOMA) and CALLY index were calculated with formulas.The diagnostic criteria for MetS recommended by the Turkish Society of Endocrinology and Metabolism were used for the diagnosis of MetS.Analysis was done using appropriate statistical methods. Results:MetS was detected in 24.5%(n=184) of the 750 people who participated in the study.The Mg/Ca ratio was lower in those with MetS.However,no statistically significant difference was observed.Although the power of the CALLY index to distinguish metabolic syndrome was weak,it was found to be statistically significant.Additionally,it was found that the risk of MetS increased by 1.05 times for each unit decrease in the CALLY index. Conclusions:The obtained data show that the CALLY index may provide additional value in identifying individuals at high risk of developing MetS.However,large-scale randomized studies are needed to fully define the biomarker's properties.