Background: Data on safety and efficacy of adjuvant chemotherapy for stage II and III colon cancer in elderly patients is area of controversy as these patients are underrepresented in clinical trials. We did a retrospective analysis of Medicare patients aged 70 or older with stage II and stage III colon cancer to investigate the adjuvant chemotherapy effect on colon cancer patients’ survival. Methods: Data was analyzed from 110, 993 men and women (≥ 70 years of age) registered in the National Cancer Database (NCDB) who were diagnosed with AJCC Stage II and Stage III colon cancer between 2004 and 2012 and had follow-ups to end of 2013. The primary predictor variable was adjuvant chemotherapy received, and overall survival was the outcome variable. Only patients with Medicare insurance were investigate for ease of analysis. Additional variables addressed and adjusted included gender, age, race, Charlson Comorbidity Index, the level of education, income, grade of tumor, distance traveled, facility type and diagnosing/treating facility. Results: The mean age was 79.5 years and SD was 5.9 years. In multivariate analysis, after adjusting for secondary predictor variables, receipt of adjuvant chemotherapy was a statistically significant predictor of overall survival of the stage II and stage III colon cancer. Relative to patients who did not receive adjuvant chemotherapy, the patients who got single agent adjuvant chemotherapy had 47.7% and those who were treated with multi agent chemotherapy had 49.8% decreased risk of mortality. There was no significant survival difference between single agent and multi agent adjuvant chemotherapy. Among the factors analyzed, age, gender, race, comorbidity index, diagnosing /treating facility and grade of tumor were found to be significant predictors of survival. Conclusions: Among the patients aged 70 years or older with stage II and stage III colon cancer, adjuvant chemotherapy lead to improved survival outcomes. However, survival difference between single agent vs multi agent adjuvant chemotherapy was not statistically significant.