Carcinoma of the colon and/or rectum represents the second most common gastrointestinal malignancy worldwide. Despite this prevalence, current therapeutic regimens remain largely ineffectual, particularly when the disease is diagnosed at an advanced stage. Recent work in the field of colorectal cancer has established that a chronic intake of non steroidal anti-inflammatory drugs can reduce the risk of developing colorectal cancer. Although the precise mechanism(s) by which these drugs inhibit tumour growth is not completely understood, it is likely that at least a part of their anti-tumorigenic effects results from an inhibition of the cyclo-oxygenase-2 enzyme. This chapter will focus on this emerging research area and the promise it brings for identifying new strategies for the prevention of colorectal cancer.