Objective: Changes in magnesium metabolism have a different effect on the metabolic and signaling pathways in the development and progression of diabetes. This study aimed to determine the relationship between the serum magnesium level and polyneuropathy in patients with type 2 diabetes mellitus (DM).
 
 Method: The study included type 2 DM patients who presented to the neurology outpatient clinic of Ankara City Hospital with the complaint of pain and burning sensation in the hands and feet and received a pre-diagnosis of polyneuropathy based on electroneuromyography (ENMG). Biochemistry and hormone parameters of patients were scanned retrospectively.
 
 Result: A total of 116 patients, 49 (42.2%) female and 67 (57.8%) male, were included in the study. When the patients were divided into three groups according to the tertiles of HbA1C, the frequency of polyneuropathy was significantly higher in the group with high HbA1C levels (P=0.004). A significant relationship was observed between the magnesium level and detection of polyneuropathy on ENMG The mean magnesium level was significantly lower in the polyneuropathy group(P=0.013). Patients with additional complications other than polyneuropathy had significantly lower magnesium levels than those without such complications (P=0.021).
 
 Conclusion: This study showed that the magnesium levels were significantly associated with the development of polyneuropathy in patients with type 2 DM. It was concluded that an adequate magnesium level in patients with glycemic control can prevent the development of diabetic polyneuropathy.