Diabetes mellitus is being increasingly seen in Tunisia where the incidence of the disease is nearing the rates seen in industrialized countries. This prospective study was carried out between February 1st, 1990, and January 1st, 1991 in the department of general surgery of a regional hospital in Nabeul, Tunisia. Patients with diabetes mellitus accounted for 3.3 % of admissions and 8 % of inpatients. Poorly controlled diabetics were more likely to develop postsurgical complications, especially infections. Postoperative mortality was also substantially higher in diabetics. These results were due at least in part to the lack of adequate means for managing patients with diabetes mellitus.