Background: Traditionally, open procedure through exploratory incisions remains the gold standard approach for treating colorectal (CRC). Laparoscopic colectomy was proved to be a better alternative to the open approach. Though in some studies, it was found that the length of the operation tends to be somehow longer. However, in experienced hands it has comparable oncologic outcomes. Moreover, the laparoscopic approach is associated with less postoperative pain, faster return of bowel activity, earlier resumption of oral intake and lesser hospital stay. Aim of the Study: to study and evaluate the effectiveness of laparoscopic left hemicolectomy and sigmoidectomy compared to the open left sided colectomy and sigmoidectomy for malignancy regarding operative time, length of hospital stay, return of bowel function, resumption of oral intake, postoperative pain perception, general postoperative complications, surgical site infections and early recurrence. Patients and methods: This comparative study has been conducted in El-Demerdash hospital, Ain Shams University - Cairo, Egypt and has included 60 patients where half of the patients underwent open left hemicolectomy or sigmoidectomy and the other half underwent laparoscopic left hemicolectomy or simoidectomy. We performed both procedures during the period between 1st of January 2016 and 1st of January 2017 with 12 months of follow- up post-operatively. Results: In our study, the laparoscopic operation was associated with less hospital stay, earlier return of bowel activity, earlier resumption of oral intake without the use of the regular anti-emetics with better pain control and perception postoperatively. Moreover, it was associated with less surgical site infections and general complications including the respiratory ones than the open operation. We had similar anastomotic leak rates and early recurrence rate between both operations. Finally, the laparoscopic operation was associated with more operative time compared to the open operation. Conclusion: Laparoscopic left hemicolectomy and sigmoidectomy are oncologically sound when compared to the open left hemicolectomy and sigmoidectomy for treating left sided and sigmoid cancers. Moreover the laparoscopic approach yielded better outcomes regarding the postoperative recovery compared to the open approach. Recommendation: A further high volume study is needed to assess the long term effects of both procedures in our hospital.