OBJECTIVE: The objective of this study was to identify the risk factors for delays in chemotherapy after rectal cancer surgery and evaluate the effects of delayed therapy on long-term outcomes. We also sought to clarify what time frame should be used to define delayed adjuvant chemotherapy. BACKGROUND: Postoperative complications have been found to influence the timing of chemotherapy in patients with colon cancer. Delays in chemotherapy have been shown to be associated with worse overall and disease-free survival in patients with colorectal cancer, although the timing of delay has not been agreed upon in the literature. STUDY DESIGN: We performed a retrospective review of a prospectively maintained rectal cancer database. Univariate analysis was used to identify risk factors for delayed chemotherapy. Kaplan-Meier curves were generated to compare overall and disease-free survival in patients based on complications and timing of chemotherapy. SETTINGS: This study was performed at the University of Wisconsin Hospital, Madison, Wisconsin, between 1995 and 2012. PATIENTS: Patients with rectal cancer who underwent proctectomy with curative intent were included in this study. OUTCOME MEASURES: Timing of chemotherapy, 30-day complications, and 30-day readmissions were the main outcome measures. RESULTS: Postoperative complications and 30- day readmissions were associated with delays in chemotherapy ≥8 weeks after surgery. Patients who received chemotherapy ≥8 weeks postoperatively were found to have worse local and distant recurrence rates and worse overall survival in comparison with patients who received chemotherapy within 8 weeks of surgery. LIMITATIONS: The limitations of this study include its retrospective nature and that it was performed at a single institution. CONCLUSIONS: We found complications and readmissions to be risk factors for delayed chemotherapy. Patients who received therapy ≥8 weeks postoperatively had worse disease-free and overall survival. © The ASCRS 2013.