The number of elderly patients with colorectal cancer is increasing in Japan. They have the opportunity to receive chemotherapy similar to non-elderly patients because of the development of new drug agents and improvement of supportive therapy. We analyzed retrospectively 184 patients (32 aged >or= 70, 75 <or=) with advanced and metastatic colorectal cancer with good performance status who received FOLFOX4 regimen between April 2005 and March 2006. We observed adverse events, time to treatment failure, response rate, reason to discontinue treatment, and dose intensity. Age <or= 70 was associated with slightly higher rates of neutropenia but no other grade >or= 3 adverse events. The FOLFOX4 regimen maintains its efficacy/safety ratio in elderly patients with good performance status with colorectal cancer in Japan.