Treating elderly patients with colorectal cancer is a challenging task for which many aspects have to be taken into account. Almost 70% of patients with colorectal cancer are 65 years or older and the number of elderly patients is expected to increase. As elderly patients frequently exhibit adverse physical or socio-economic conditions, a thorough geriatric assessment of the patient's suitability for therapy is essential before making a decision. The first line treatment for colorectal cancer is surgery. Complete resection of the tumor should also be attempted in elderly patients, as there are little differences in cancer--specific survival in selected elderly patients compared to younger patients. Surgery with palliative intention can be attempted for symptom control or to prevent later local complications caused by the primary tumor. At present, adjuvant 5-FU based chemotherapy (in colon cancer) and adjuvant radio-chemotherapy (in rectal cancer) in the elderly is recommended for locally advanced or node positive tumor after tumor resection, since the benefit seems to be comparable to that achieved in younger patients. There is also enough data to support the use of 5-FU based chemotherapy in elderly patients in the palliative setting. New drugs have recently been added to the armentarium for the treatment of metastatic colorectal cancer. However, there is as yet not sufficient data to guide the use of these new drugs (such as oxaliplatin or irinotecan) in elderly patients. However, first clinical studies seem to indicate a comparable efficacy and toxicity in elderly patients to that observed in younger patients. Further clinical trials of chemotherapy in elderly patients with colorectal cancer are necessary to gain information about treatment recommendations. It is the aim of this manuscript to summarize the current knowledge about the management of colorectal cancer in elderly patients.