AIM and METHODS: The  purpose  of the  study  was  to  characterize  the  time-related effect of Danazol therapy on endometriosis explant using the rat model. Endometriosis was induced in mature female rats. One  group of treated animals as well as controls  were  sacrificed  at  2,4,6 and 8 weeks after treatment at which time the explant was evaluated. RESULTS: Explant  volume  was significantly reduced in all treatment groups, and the effect  was more significant in animals  treated for   4 weeks than  those treated for only 2 weeks.  CONCLUSION: Danazol  treatment can   cause gradual regression of endometrial explant in a time-related manner.