Objective To estimate the operative risk and outcomes of colorectal cancer patients 80 years of age and older. Methods Colorectal cancer resection was performed in 99 patients 80 years of age and older between Dec. 1987 and June 2005. The informations about clinical data, co-morbidity,complications, operative mortality and survival were retrospectively analyzed. The patients were followed-up for 45.12 months (range 1-136) months. Results Of 99 patients, co-morbidity was found in 43 patients (43.4% ) and complication in 10 patients (10.1%). No patient died of operation.Eighty patients completed the follow-up study. The overall 3-year survival rate and disease-free survival rate were 64.3% and 61.1%, respectively. Whereas the overall 5-year survival rate and disease-free survival rate were 52.8% and 52.1%, respectively. In univariate analysis, curative or palliative operation, tumor differentiation, cancer embolism in the vasculature, tumor staging and complications were proved to be significant prognostic factors. Multivariate survival analysis,however, showed that only the curative or palliative operation was independent factor for survival.Conclusions The high risk of co-morbidity for patients 80 years of age and older is not the obstacle to cancer resection.These patients will have satisfactory outcomes via optimal treatment and operation.