A 29-year-old-woman with recurrent cancer of rectum was treated with Etoposide, cis-platinum and external irradiation. Previous postoperative chemotherapies consisted of MMC, CPA, VCR and HCFU. Histologically, the tumor invaded in sheets and nests, and consisted of round to ovoid malignant cells with high nuclear/cytoplasmic and hyperchromatic nuclei with a coarse, clumped, or stippled chromatin pattern. Most cells demonstrated a positive reaction by Grimelius and NSE staining. Eight months after surgery, we switched to Etoposide cis-platinum and external irradiation, because of local recurrence. Etoposide (total 725 mg) and cis-platinum (total 100 mg) were injected into bilateral iliac artery and 60 Gy radiotherapy was performed. The patient showed a good response, and a complete response (CR) was evident for the following 42 months. Thus, Etoposide, Cis-platinum and radiotherapy are considered an effective combination therapy for a patient with small cell undifferentiated carcinoma.