Objective: • To study about the 'perioperative' glycaemic control and postoperative infections. • To study about the postoperative glycaemic status and postoperative infections. • To study the range of the blood sugar to be maintained Methods: All patients with diabetes mellitus who underwent elective and emergency surgeries are studied with perioperative blood sugar values and postoperative wound infections, urinary tract infections, lower respiratory tract infections and sepsis Results: The incidence of surgical site infections in these patients were proportional to the glycaemic control achieved, the highest being in the fourth quartile(261-350md/dl) patients i.e. 100% and the least being in the first quartile patients(120-180mg/dl) i.e.16.6%. In the glycaemic range above 260mg/dl almost all patients had surgical site infections invariably stressing the importance of strict glycaemic control in these patients to avoid long hospital stay and the health care expenditure that results. Conclusion: It is conclusive that the incidence of postoperative infections in patients with diabetes undergoing surgeries is higher with greater mean plasma glucose levels. patients with control mean sugar values were free of surgical postoperative complications.