The instant invention is directed to the use of cyclooxygenase-2 selective inhibitors to treat or prevent endometriosis; the use of cyclooxygenase-2 selective inhibitors to prevent, retard and/or reverse the development of endometriotic lesions in patients at risk for the development of such lesions; the use of cyclooxygenase-2 selective inhibitors to reduce the number and/or severity of endometriotoc lesions in patients at risk for the development of such lesion; and the treatment of pain in such patients. Combination therapies are also encompassed.