An 83-year-old female. At 82 years of age, the patient sought evaluation with a complaint of rectal bleeding. A 35-mm rectal gastrointestinal stromal tumor(GIST)was treated by laparoscopic ultra-low rectal resection and transanal anastomosis following trans-anal rectal dissection by perineal manipulation. Approximately 1 year later, a 20-mm metastatic lymph node within the right lateral lymph node group at the pelvic cavity was detected. The patient was diagnosed with a recurrence of rectal GIST. The patient had no symptoms and did not wish to undergo surgery. After 7 weeks of treatment with an imatinib dose reduction(200 mg), the dosage was increased and the patient was admitted to the hospital with edema of the face and lower limbs, and pleural and pericardial effusions(grade 2). After discharge from the hospital, the medication was terminated early at the patient's request. One year later, the lymph nodes had decreased in size to 7.5 mm, indicating a partial response. The treatment-free period continued, and after 5 years at 89 years of age the lymph nodes had not enlarged, thus the patient was thought to be clinically cured. We report a rare case of long-term tumor suppression using short-term low-dose imatinib therapy.