The incidence of synchronous carcinoma of colon-rectus is rising in relation to a greater oncogenic environmental charge and increased average life expectancy. There is also a risk of not recognising the disease (especially small carcinoma or multicentric neoplasm). After a Literature review, two clinical cases are described by the authors. They recommend an extensive use of preoperative colonoscopy and a careful intraoperative exploration of the viscera. It is also important that patients undergo periodical postoperative endoscopic controls.