Acute diverticulitis requiring surgical intervention has conventionally been treated by resection with colostomy or delayed resection with primary anastomosis at a second admission. Our objective was to determine the outcome for treatment of diverticulitis with resection and primary anastomosis during the same hospitalization. We conducted a retrospective review of patients (n = 74) undergoing surgery for diverticulitis. Groups included: 1) resection with primary anastomosis (n = 33), 2) resection with colostomy followed by a takedown colostomy (n = 32), and 3) delayed resection with primary anastomosis at a second admission (n = 9). Despite local perforation primary anastomosis was often performed unless patients were clinically unstable or had fecal contamination. The operation was urgent in five (15%) patients in Group 1 as compared with 26 patients (88%) in Group 2. Serious intra-abdominal complications occurred in two patients (6%) in Group 1 as compared with nine patients (28%) in Group 2 and one patient (11%) in Group 3. Postoperative abscesses occurred in two patients in Group 1, five patients in Group 2, and one patient in Group 3. We have shown that resection with primary anastomosis for acute diverticulitis--even in selected patients requiring urgent operation--can be safely performed during the same hospital admission with a low complication rate.