Extensive diagnostic and therapeutic interventions are particularly problematic and dangerous for diabetic patients. Metabolic derangement, cardiovascular, renal, neurological, psychiatric and thromboembolic complications are not uncommon. Additionally, in cases of inadequate preoperative metabolic adjustment further perioperative complications, such as wound healing disorders and general infections are possible. Multimorbidity, the necessary polypharmacy, early hospital discharge, insufficient training of physicians and nursing personnel for this complex disease, financial pressures and inadequate preoperative preparation of patients before elective interventions are the essential reasons for the above average frequency of perioperative and postoperative complications in diabetic patients. The care of adults with this disease is discussed from the preoperative period up to discharge and detailed recommendations are given for the perioperative management of antidiabetic drugs.