Improved regional control as demonstrated by a lower incidence of local recurrence after concurrent chemoradiation delivered either pre-operatively or post-operatively for resectable rectal cancer is supported by clinical trial data but the impact on overall survival with either approach remains controversial. An ideal regimen for preoperative chemoradiation in locally advanced rectal cancer would include agents that are both potent radio-sensitizers and effective in treating micro-metastatic disease without excessive toxicity. The cyclooxygenase-2 (COX-2) enzyme is over expressed in colorectal cancer, but the exact role of this over expression in tumorigenesis remains an active area of research. The area with the most potential in using cyclooxygenase-2 inhibitors in cancer treatment may be to use them as an adjunct to other modalities of treatment.