The submitted paper should serve as a basis for recommended procedures of preoperative and postooperative care of diabetics. It contains the algorithm of preoperative preparation of diabetics focused on quantification of the risk of surgery. The diabetologist is the consultant of the surgeon who participates in the preparation of the patient for urgent as well as elective surgery. The procedures differ with regard to the type of diabetes. The authors mention in more detail the problem of preoperative care of operated diabetics and finally also monitoring and therapy of diabetics during the postoperative period.