An Observational Study was undertaken at Department of Otorhinolaryngology and Head and Neck Surgery, AIMSR from Jan 2019 - August 2020. The aim of this study was to observe the outcome of endoscopic tympanomastoidectomy for attico-antral type of CSOM. All the patients attending ENT OPD at AIMSR within the age group of 11-60 yrs, irrespective of sex with Attico-Antral CSOM either unilateral or bilateral were included in this study. However, revision mastoidectomies, patients with intracranial complications of CSOM or actively discharging ear, or patients with external and middle ear abnormalities either congenital or acquired, medically and surgically unfit patients and Patients unwilling to take part in study were not included. In our study of 50 patients, 40 patients had graft uptake after disease clearance and 8 had failure of graft uptake without chronic otorrhoea and 2 had failure with chronic otorrhoea. Through this study we concluded that Endoscopic Tympano-mastoidectomy for attico-antral type of CSOM is an excellent technique for complete removal of cholesteatoma especially from inaccessible areas of middle ear cleft.