BackgroundColorectal cancer (CRC) is one of the most common cancers worldwide which is not extensively researched in Iran.ObjectivesThe present study aims to investigate the epidemiologic characteristics of CRC in patients referred to selected hospitals of Tehran University of Medical Sciences.Patients and MethodsIn this descriptive-analytic study 218 patients with colorectal cancer were investigated. Data were collected via reviewing recorded pathologic results of patients of these hospitals which then were analyzed by univariant methods.ResultsAmong 218 patients, 140 (64.2%) were male and 78 (35.8%) were female. Of all patients, 132 (60.0%) suffered from tumors in rectum; 38 (17.4%) in sigmoid; 12 (5.5%) in descending colon; 10 (4.6%) in transverse colon and 26 (11.9%) in ascending colon and cecum. Tumors were well differentiated in 134 patients (61.5%), moderately in 62 cases (28.4%) and poorly differentiated in 22 patients (10.1%). There was no significant difference between males and females regarding the location and degree of tumor differentiation.ConclusionsRegarding high prevalence of colorectal cancer in Iran and potential environmental and genetic factors, surveillance must be considered for this disease. Its risk factors such as diet, life style and low physical activity should be evaluated and screening should start at younger ages.