Magnesium, the second most abundant intracellular cation, is a necessary cofactor for hundreds of enzymes and plays an essential role in protein synthesis. It is usually aecepted that plasma magnesium concentration is stable in healthy people, but hypomagnesemia is a common finding in diabetic sujects. Many authors described the presence of substantial hypomagnesemia in a large series of diabetic patients and reported a close relationship between hypomagnesenaia and poor diabetic control. To evaluate a relationship between hypomagnesemia and metabolic control, HbAlc,serum albumin and other variable.; in diabetes, 117 diabetic patients were analysed. The mean serum magnesiurn concentrations in 117 diabetic patients was 2.14+-0.35 mg/dl. Serum magnesium concentration correlated best with HbAlC value (r=-0.32, p<0.005) and secondly with postprandial 2 hours sugar (r-= -0.28, p<0.01). But .serum magnesium concentration correlated not so significantly with fast- ing blood sugar, serum albumin, serum potassium, type of treatment, diabetic duration, age and body mass index. Conclusively our data suggest that measurement of serum magnesium concentration provide. A useful means to assess the metebolic control in diabetes,