We experienced a case of locally advanced sigmoid colon cancer with obstructive symptom, that could be resected after chemotherapy under colonic stent placement. A 61-year-old male came to our hospital suffering from anal bleeding. After some examinations a diagnosis of colonic obstruction due to sigmoid colon cancer (CROSS1) was made. At first, a colon stent was inserted. Then, the patient was administered four courses of SOX (S-1+Oxaliplatin) therapy. No significant adverse effects were observed during chemotherapy. Subsequently, laparoscopic assisted sigmoid colon resection was performed. R0 excision was achieved. The effect of chemotherapy was Grade 3. It is controversial whether chemotherapy for advanced colorectal cancer cases can be performed under stent placement. However, for the treatment of locally advanced cancers with obstruction, we considered that systemic chemotherapy under stent placement can be a treatment option if there is a possibility that the tumor can be reduced by systemic chemotherapy, after obtaining sufficient informed consent.Nevertheless, further investigation of these cases should be performed.