From August through October 1962, during 2 months, author has experienced 24 cases of muscluo-mastoidplasty in which a temporalis muscle was used to obliterate the mastoid cavity. Those were carried out at the National Medical Center, and a study was made in special regard to the effect of this obliterative mastoid operation on healing and ceasing of otorrhea. The 24 cases had a history of recurrent drainage more than 5 years prior to surgery. In an attempt to compare the result of this technique with that of non-obliterative mastoidectomies, 32 cases of control group were selected. In the musculo-mastoidplasty group, healing was obviously rapid compared with the control group. Three quarters of the ears became dry within 6 weeks, while a couple of cases out of the 24 showed persistant ear-discharge more than 6 months that called for eventual revision. As an undesirable complication, five cases presented postoperative stenosis of external auditory canal 2 to 4 weeks after surgery.