Between 1976 and 1986, a consecutive series of 195 patients with right colon cancer were admitted at the First Department of Surgery of the University of Rome. Patients were divided into five groups according to the absence of intestinal symptoms (group 1) and the duration of the symptomatic phase (groups 2-5). Analysis of the preoperative investigation showed that colonoscopy was able to identify 33 (26.2%) of tumors misdiagnosed by double contrast X-ray barium enema. We did not notice any correlation among symptom duration and tumor stage, tumor differentiation, operability rate, and survival. Patients admitted in the asymptomatic phase presented tumors of less advanced stage and, thus, had the best survival rate (71.4%). In this group, patients promptly treated had a better survival rate (87.5%) than those treated after 2 months (50%). Our study suggests that only neoplasms diagnosed in asymptomatic patients and treated promptly are related to a good survival rate. We, therefore, emphasize the importance of education of patients and family physicians about right colon cancer and the necessity to investigate all patients with a suspected right colon cancer by means of colonoscopy.