Colon diverticulitis showed a great variability in kind, intensity and course of disease. Time and surgical procedure are dependent on the stage of diverticulitis (emergency procedure, elective resection, early elective resection). In emergency cases non-resecting procedures should not be performed. Here the Hartmann procedure and in favorable conditions the primary resection should be chosen. Other patients with acute diverticulitis should have early elective resection after short-term medical treatment (5-7 days). Patients with a chronic-recurrent course of disease should have an elective one-sided resection. The surgical principles are mobilization of the splenic flexure as well as the widening of the distal resection limit into the upper rectum to avoid a recurrence.