All patients with perforated diverticulitis admitted as emergency cases and having undergone colon resection during their initial hospitalisation in the period from 1 January 2003 to 30 June 2008 at one institution were analysed with regard to morbidity and mortality. The group consisted of 106 patients (mean age 65 years, range 32-98 years), 60% of whom had comorbidity. Hartmann's procedure was the initial procedure in 77% and primary resection and anastomosis in 23%. Of these patients 18% underwent reoperation, leading to a mean number of surgical procedures during the initial hospitalisation of 1.3 (range 1-10). The mean length of stay was 17 days, the median stay 12 days (range 1-111 days). A total of 43% of the patients underwent surgery during readmissions. Among the 82 patients operated with Hartmann's procedure, permanent stoma was the end result for 35 patients (43%). Six patients died. This retrospective study confirmed that perforated diverticulitis requiring colon resection was associated with a high risk of reoperation, long hospital stay, readmittance with renewed surgery and permanent stoma. Furthermore, the procedure caused suffering and a considerable drain on resources. The results will be used as the basis for a randomised trial on laparoscopic lavage versus Hartmann's procedure.