Background: Diabetic foot ulcers (DFU) is one of the significant complications of diabetes mellitus, as it might lead to limb amputations which results in a major medical and economic consequences for both patients and their families. Magnesium (Mg2+) is a cofactor in the glucose-transporting mechanism. It is involved in the optimal insulin secretion and/or action. Aim: The aim of this study is to assess the relationship between the hypomagnesemia and the risk of DFUin Sudanese diabetic patients. Method: A cross sectional study was conducted in 117 subjects, out of which; 54 are diabetic patients with DFU as cases and 63 are diabetic patients without foot ulcers as controls. Serum Magnesium levels were measured for both groups using Spectrophotometer Result The results of this study showed that 64.8% of the DFU patients were males with significant gender difference between DFU (cases) and DM (controls) (P = 0.032). The highest frequency of the cases and controls (92.6% and 87.3% respectively) are at age ≥ 45 years with no significant difference between the two groups (P =0.24). Serum Magnesium level was measured for both cases and controls. The study revealed that serum hypomagnesemia was reported with high frequency (87%) among DFU patients, with a high significant association with the diabetic foot ulcer susceptibility (DFU) compared to (DM) controls (P = 0.001). Highest prevalence of hypomagnesemia among cases (85%), who have the diabetes for five to fifteen years was observed compared to their counterpart controls, with an extremely statistical significance between the two groups (P =0.0001). This indicates an exponential decrease of magnesium level with an increase of disease duration. Neuropathy; not only represent the highest frequency of the diabetic complication among the DFU patients (37%), it strongly associated with a five folds increased risk to DFU (OR=5.5). Retinopathy was observed in both DFU and DM patients 29.6% and 38% respectively. Conclusion: This study proposed that hypomagnesemia is a significant risk factor to develop diabetic foot ulceration among diabetic patients. Magnesium level was strictly decreased with the increase of diabetes duration.