A 60-year-old-man underwent initial resection of a rectal tumor, with a transanal approach, on December 6, 2000. The tumor was diagnosed as a gastrointestinal stromal tumor(GIST) by KIT and CD34 immunohistochemistry. In June 2003, a third recurrence in the rectum was discovered, at the same location as the initial tumor, and he was referred to our hospital. Magnetic resonance imaging (MRI) revealed a tumor 3.0 cm in diameter, compressing the prostate anteriorly. After the oral administration of imatinib mesylate (Gleevec, Glivec) at a dose of 400 mg per day for 3 months, the size of the tumor had decreased to 1.2 cm in diameter. On December 12, 2003, a fourth operation was performed successfully, with a perineal approach, preserving sphincter function. More than 40 months after the fourth operation, neither local recurrence nor distant metastasis was detected. Our strategy of treatment with imatinib allows not only complete excision of the tumor but it also reduces postoperative impediments in patients with recurrent rectal GIST.