Introduction: Diabetes Mellitus is a common endocrine disorder. Glycemic control in Diabetes Mellitus is very important. Our aim in this study was to prove that Magnesium levels can be used a marker for the glycemic control in Diabetes Mellitus. Methods: A total of 118 patients who were diagnosed with Diabetes Mellitus Type II by HbA1c were enrolled in this study. Detailed history, physical examination and relevant systemic examination was done. HbA1c levels, fasting blood glucose, post-prandial blood glucose levels and Mg levels were obtained from the patients. Results: The mean age of the patients was 47.96±6.89 years and the median age was 52 for males. Patients were divided in 2 groups as Mg levels <1.38mg/dl and >1.38mg/dl. We found that in patients with low levels of Mg (<1.38mg/dl), HbA1c was 9.45±1.28 and in patients with Mg levels of >1.38mg/dl, HbA1c was 7.01±0.95 (p value <0.001). FBS was 145.78±12.47mg/dl in patients with Mg levels <1.38 and 120.19±11.60mg/dl in patients with Mg levels >1.38(p value <0.001). PPS was 191.07±20.94mg/dl in patients with Mg levels <1.38 and 158.04±15.35mg/dl in patients with Mg levels >1.38(p value <0.001). Conclusion: Serum magnesium levels are inversely co-related with the glycemic control in type II Diabetes Mellitus. Poor glycemic control was seen with patients with low levels of Magnesium.