Colorectal cancer is a leading cause of morbidity and mortality with about 300,000 new cases and 200,000 deaths in Europe and the USA each year. Published trials have established a role for chemotherapy in colorectal cancer, in the adjuvant setting for Dukes C colon cancer, with an absolute survival benefit of about 5% and in advanced colorectal cancer, for which it improves quality of life and increases survival by 6-12 months. For rectal cancer, radiotherapy decreases rates of local recurrence and, in locally advanced disease, successfully palliates pain, tenesmus, and bleeding. The evolving understanding of colorectal carcinogenesis, in particular recognition of vital genes that may be mutated or lost during tumour development, has been translated into innovative gene therapy techniques. Finally it is increasingly apparent that surgical site specialisation and a multidisciplinary approach (including surgeons, pathologists, and oncologists) may lead to optimum outcomes for patients with colorectal cancer.