OBJECTIVES Preoperative or postoperative radiotherapy has been used to decrease local recurrence and thereby improve survival. Previous studies comparing these two types of treatments have given conflicting results. The study aims to compare the efficiency of preoperative versus postoperative radiotherapy in terms of survival for resectable colorectal cancer (Stage II and III). METHODS The study has been carried out on patients with resectable colorectal cancer in stage II and III. It is based on the data recorded by National Cancer institute, Surveillance Epidemiology and End Results (SEER) 17 registries data between year 1999 and 2005. Survival analysis was used to assess the patients exposed to radiotherapy as an adjuvant therapy before or after surgery and a comparison of survival time in between the two groups was done using the log rank test. RESULTS A total of 12,134 patients were subjected to radiotherapy as adjuvant therapy. Out of which 7481 were administered with radiation after surgery and 4653 patients with radiation prior to surgery were taken into consideration for the study. Patients who have been administered radiotherapy after surgery have shown longer survival time (43 months) than patients administered with radiotherapy before surgery (33 months) (p=0.000). The survival time difference may also be attributable to the Stage of the cancer. The survival time for Stage III patients receiving radiation after surgery is longer than patients administered with radiation before surgery (43 months vs. 29 months; p=0.000). No significant survival difference was observed in Stage II patients. CONCLUSIONS The study should assist the clinician in forming a preliminary opinion for further investigations pertaining to the sequence of radiation with surgery as adjuvant therapy for resectable colorectal cancer. Further studies should also investigate the influence of demographics, dose of radiation and co-morbidity on survival time in the resectable colorectal cancer cases.