Acute perforated diverticulitis of the colon is still a serious clinical event that requires an emergency treatment which is based upon clinical staging and pathological characteristics. Surgical treatment, performed in Hinchey's stages III and IV, is correlated with the presence of infection in the peritoneal cavity: it is always necessary to remove the septic focus, but there are different reconstruction strategies. The resection of the diseased colonic segment can be performed with primary anastomosis or Hartmann's operation with reconstruction in a later time. In our experience, based on 97 patients (33 of which, Hinchey's III and IV, underwent emergency surgical treatment) we preferred Hartmann's operation which carries a low risk of mortality in seriously ill patients.