Objective: Circumferential resection margin status is one of the strongest predictors in rectal cancer. The aim of this study was to identify rate of circumferential resection margin (CRM) involvement after rectal cancer excision. The relationship between CRM status and clinicopathologic characteristics of rectal cancer was also evaluated. Material and method: In this cross sectional study, surgical specimens from patients with rectal cancer who underwent surgery according to principles of total mesorectal excision (TME) between March, 2010 and June, 2011 were extracted at Can Tho Central General Hospital. Whole - mount section technique was used to evaluate CRM status. Results: All data and CRM of 49 patients were collected. 12 patients (24.5 percent) hacl positive circumferential resection margin (CRM (+". Some factors that increase the frequency of CRM (+) are: circumferential location (p = 0.025), tumor size 5 cm (p = 0.001), poor differentiation (p = 0.027), T stage (p = 0.02), nodal involment (p = 0.014). Conclusion: Circumferential resection margin is involved in 1f4 patients with rectal cancer. CRM involvement is significantly associated with circumferential location of tumor, tumor size, grade of differentiation, depth of tumor invasion, lymph node involvement.