Colorectal cancer (CRC) is now a major concern for many developed and developing countries. In the past, most cases of this cancer were found in developed countries and were considered a disease of western life style. In recent years, the incidence of CRC has been increasing in the developing countries, due to changes in life style, which include a more sedentary life style, obesity, alcohol intake and smoking habit. In USA, CRC was the second most common cause of death among all cancer cases and the incidence was higher among males than among females. In United Kingdom, CRC was the third most common cancer occurring in both males (after lung and prostate cancer) and females (after breast and lung cancer). Other countries that have reported a high incidence of CRC included Canada, Australia, New Zealand, Denmark, and Sweden. In Australia, CRC was the second most common cause of death among all cancer cases. CRC also has become the third most common cancer cases among males and females in Asia. Asian countries that reported high incidence of CRC included Japan, Singapore, South Korea, Taiwan, Hong Kong, and Iran.