Background The short-term results of the Sigma trial show that laparoscopic sigmoid resection (LSR) used electively for diverticular disease offers advantages over open sigmoid resection (OSR). This study aimed to compare the overall mortality and morbidity rates after evaluation of the clinical outcomes at the 6-month follow-up evaluation. Methods In a prospective, multicenter, double-blind, parallel-arm, randomized control trial, eligible patients were randomized to either LSR or OSR. The short-term results and methodologic details have been published previously. Follow-up evaluation was performed at the outpatient clinic 6 weeks and 6 months after surgery. Results In this trial, 104 patients were randomized for either LSR or OSR, and the conversion rate was 19.2%. The LSR approach was associated with short-term benefits such as a 15.4% reduction in the major complications rate, less pain, and a shorter hospital stay at the cost of a longer operating time. At the 6-month follow-up evaluation, no significant differences in morbidity or mortality rates were found. Two patients died of cardiac causes (overall mortality, 3%). Late complications (7 LSR vs. 12 OSR; p = 0.205) consisted of three incisional hernias, five small bowel obstructions, four enterocutaneous fistulas, one intraabdominal abscess, one retained gauze, two anastomotic strictures, and three recurrent episodes of diverticulitis. Nine of these patients underwent additional surgical interventions. Consideration of the major morbidity over the total follow-up period (0-6 months) shows that the LSR patients experienced significantly fewer complications than the OSR patients (9 LSR vs. 23 OSR; p = 0.003). The Short Form-36 (SF-36) questionnaire showed significantly better quality of life for LSR at the 6-week follow-up assessment. However, at the 6-month follow-up assessment, these differences were decreased. Conclusions The late clinical outcomes did not differ between LSR and OSR during the 30-day to 6-month followup period. Consideration of total postoperative morbidity shows a 27% reduction in major morbidity for patients undergoing laparoscopic surgery for diverticular disease.Keywords Diverticular disease Á Diverticulitis Á Sigmoid resection Á Laparoscopic Laparoscopic surgery for the treatment of diverticular disease has gained popularity over the past two decades. Particularly in an elective setting, laparoscopic sigmoid resections (LSRs) have shown beneficial effects on postoperative outcomes [1,2]. Traditionally, elective open sigmoid resections (OSRs) have been associated with high postoperative complication rates and a mortality rate of