Coexisting primary malignancies have been presented in the medical literature for many years. A particularly interesting group is tumours developing in the digestive system. The authors present a case of sychronous coexisting adenocarcinoma transverse colon and carcinoid in the distal part of the small intestine. Clinical symptoms of transerse colon cancer camouflage the presence of second primary malignancy – carcinoid. Therefore this report apart from presenting quite a rare case emphasizes the role of careful intraoperative assessment, which can modify operation range and determine the patient’s fate.