Background: Magnesium is a critical ion that is essential for life. It is intimately involved in over 300 enzymatic reactions. It also has important endocrine functions and is required for protein synthesis. Studies have shown that magnesium levels are lower in patients with diabetes compared with non-diabetic controls. Hence this work was undertaken to evaluate the relationship between serum magnesium and diabetes mellitus without and with microvascular complications. Aim: To compare the serum magnesium levels in type 2 diabetes mellitus patients with and without micro vascular complications. Objectives: To estimate serum magnesium levels in type 2 Diabetes mellitus, to correlate serum magnesium level in type 2 diabetics with and without micro vascular complications.