The surgical treatment of acute, complicated diverticulitis remains controversial. No randomized studies have been performed to clarify which operative procedure best fits each situation. As a result, the surgeon must use accumulated knowledge and judgment to make the correct decisions for an individual patient. The morbidity and mortality of patients with complicated diverticular disease in 1993 depend, not so much on the operative procedure, but on the severity of the disease and the associated comorbid conditions, namely the presence of fecal or purulent peritonitis, past medical problems, immune status, and nutritional status. However, adherence to the several principles detailed in this report will minimize morbidity and mortality. The surgeon should always attempt to convert the patient from an emergency to an urgent or elective operative status. In the absence of free perforation, this goal usually can be achieved. Rushing into surgery in patients with a normal immune system is generally ill advised. It is far preferable to stabilize the patient, percutaneously drain abscesses if possible, prepare the bowel before exploration, and thus keep the option of primary anastomosis open. A primary anastomosis done first thing in the morning is far preferable to an end- stoma created in the middle of the night in an emergency situation. The algorithm displayed in Figure 1 provides a useful guideline for treating patients with complicated diverticulitis.