Introduction: Design and implementation of screening programs in each country must be based on epidemiological data. Despite the relatively high incidence of CRC, there is no nationwide comprehensive program for screening in Iran. This study was designed to investigate national CRC data and help to determine guidelines for screening. Methods: Incidence data used in this study were obtained from Iranian annual of National Cancer Registration report. Age standardized rates (ASR)were calculated using world standard population and were categorized by age, sex, anatomic subsite and morphology of tumor. Data were analyzed using SPSS.V.13 and Open Source Epidemiologic Statistics for Public Health software (OpenEpi v.2.3.1). Results: A quarter of cases were less than 50 years of age. The majority of tumors were detected in the colon. The overall ASR in the four years period was 38.0 per 100000 and was higher for men compared women (P<0.05). Incidence rate of colorectal cancer increased with age. Conclusion: Results of present study indicated that incidence of colorectal cancer is relatively high in Iran. Incidence of CRC in people under 50 years and in rectum were reported higher than other countries that related etiologic factors should be investigate in further studies. According to the increasing of ASR after age 50 years, it seems that onset of screening at age 50 would be appropriate.