OBJECTIVE To investigate the incidence of major low anterior resection syndrome (LARS), using the LARS score, in patients who underwent sphincter-preserving surgery for rectal cancer, and to explore the factors affecting major LARS development. METHOD The medical records were retrospectively reviewed of patients, who were operated for rectal cancer at a tertiary center between January 2009 and October 2017. The inclusion criteria were: The absence of other colorectal or proctologic diseases, the application of anterior resection (high anterior resection, low anterior resection, extremely low anterior resection), follow-up of more than one year after the primary surgery, and follow-up of more than one year after protective ileostomy closure, and the absence of an unreversed stoma, ongoing treatment with chemotherapy or radiotherapy, recurrence, and metastatic disease. LARS was diagnosed using the LARS score developed by Emmertsen and Laurberg. RESULTS For the study period, 81 patients met the inclusion criteria, including 45 (55.5%) men and 36 (44.4%) women, with a mean age of 60.1 years. Of the 81 patients, 56 (69.1%) underwent chemotherapy and 43 (53%) underwent radiotherapy. Major LARS was detected in 29.6% of the patients. Univariate analysis revealed that radiotherapy, lower tumor location and a short interval after ileostomy closure had an effect on LARS development, and multivariate analysis indicated that incidence of LARS was higher in middle and lower rectal cancer. CONCLUSIONS There appears to be no harm in creating a protective ileostomy for LARS development, with regard to anastomosis safety and the planning of the adjuvant therapy. Neither radiotherapy, nor type of surgery had an effect on major LARS. As was expected, a high rate of major LARS was reported in lower rectal tumors.