Background Today, with improvements in laparoscopy technique, surgery of rectal cancer is performed by laparoscopy. Objectives This study was performed to evaluate oncologic results of open versus laparoscopic surgery of rectal cancer in terms of resection margins, removal of lymph nodes and recurrence rate. Patients and Methods This descriptive-analytic study was performed on 88 patients with middle and lower rectal cancer in the two equivalent groups of laparoscopic and open surgery in Mashhad Ghaem and Omid hospitals during 2011 - 2013. Information including age, sex, number of removed and involved lymph nodes, proximal, distal, and radial margins, tumor stage and location, recurrence and disease-free survival collected in the questionnaire and analyzed using descriptive statistics and frequency distribution tables and t-test. Results Both groups of open and laparoscopic surgery had similar characteristics of age, sex, recurrence and disease-free survival, tumor margins and one-year mortality. The number of removed and involved lymph nodes was higher in the laparoscopic group (5.16 vs. 3.55, respectively, with P < 0.050, and 1.74 vs. 0.59 with P = 0.023), but the ratio of involved lymph nodes to the total number of removed lymph nodes was not different between the two groups (LNR) (P = 0.071). Tumor stage was higher in the laparoscopic group and most were in stages II and III (P < 0.001). Conclusions Laparoscopic surgery is an effective technique for safe margin and removing lymph nodes in rectal cancer.