Abstract: The endometriosis treatment protocol provides for administering to a female patient in need of treatment for endometriosis a pharmaceutical composition in a form suitable for vaginal or rectal delivery having a pharmaceutically effective amount of an aromatase inhibitor, which may be either a steroid or non-steroidal. The pharmaceutical composition may be formed as a vaginal suppository, a rectal suppository, a vaginal gel, a rectal gel, a vaginal cream or a rectal cream. The pharmaceutical composition may optionally have pharmaceutically effective amounts of progesterone and calcitriol, and may be administered in combination with an oral COX-2 inhibitor. Alternatively, the pharmaceutical composition comprises an aromatase inhibitor administered vaginally or rectally and is administered in combination with oral calcitriol and the oral COX-2 inhibitor. The aromatase inhibitor is either steroidal or non-steroidal.