The majority of patients with colorectal cancer (CRC) are >/=65 years of age, yet older patients with CRC remain under-represented in clinical trials. Older adult patients may be more likely than younger patients to experience chemotherapy-related toxicities due to factors such as existing comorbidities, incompatibility of chemotherapy with other medications, and age-related reduction in the detoxification and elimination potential of the liver and kidneys. However, the older patient group are a heterogeneous population. The available data on treatment of older patients with CRC indicate that fit older adult patients have the potential to derive the same benefit as do younger patients. A comprehensive geriatric assessment can help to identify patients most likely to benefit from standard treatment. In this review, we will evaluate the chemotherapy regimens investigated in older adult patients with CRC, and how the safety profiles and efficacy of chemotherapy in the older adult compare with those observed in younger patients.