The patient was a 76-year-old woman. One year ago, she was diagnosed as ascending colon cancer with the multiple metastases. Chest and abdominal CT showed more than 50 metastases in the liver, lung metastasis and the lesser curvature lymph metastases. She was received chemotherapy (mFOLFOX6, 5-FU/LV regimen). After 10 months, CT showed disappearance of lung metastasis and a reduction of liver metastases. We diagnosed as resectable. She had undergone right hemicolectomy, dissection of the lesser curvature lymph nodes, partial hepatectomy (17 places) and microwave coagulonecrotic therapy for liver metastases (20 places). After the operation, the number of platelets decreased from 14 × 10(4) to 30 × 10(4)/mm3. Anticoagulant therapy was effective and the platelet count increased. Postoperative bleeding, infection and liver dysfunction were not confirmed. We assumed the cause of thrombocytopenia was local intravascular coagulation due to ablation of the liver.