Colorectal cancer is a major problem worldwide and in the United Kingdom it is responsible for some 20,000 deaths per annum. 1 Mortality from the disease is gradually decreasing in developed countries but, in the United Kingdom at least, its incidence is on the increase. 2 In this article the major current challenges in colorectal cancer will be dealt with under the following headings: aetiology and prevention, early detection, diagnosis, surgery, adjuvant therapy and management of advanced disease