Essential thrombocythemia(ET)is a rare myeloproliferative disorder characterized by thrombocytosis and a risk of thrombotic and hemorrhagic events. ET rarely occurs simultaneously with colorectal cancer. Including our case, only 5 cases of c o l orectal cancer with ET have been reported in Japan. Herein, we report a case of colon cancer in an ET patient who underwent laparoscopic right hemicolectomy. Our perioperative management avoided complications such as thrombosis or bleeding. An 81-year-old woman developed bloody stools. She was previously diagnosed with ET 9 years ago. Aspirin, cilostazol, and hydroxyurea(HU)were prescribed. Colonoscopy revealed a tumor at the ascending colon. Histopathological examination showed a well-differentiated tubular adenocarcinoma. Since the patient had anemia, aspirin and cilostazol were discontinued after diagnosis. HU was discontinued from the day before surgery to 2 days after surgery. Enoxaparin was subcutaneously administered for 1 to 3 days after surgery. Aspirin and cilostazol were resumed on the fourth day post-surgery. The patient could be discharged when her condition stabilizes with no thrombosis and bleeding after 8 days.