Introduction: Chronic suppurative otitis media (CSOM) is a chronic inflammation in the middle ear and mastoid space that repeatedly secretes through the perforated membrane of tympanic disease over three months. This disease is a critical cause of hearing in developing countries. The prevalence of CSOM in Indonesia is 3.8%. Improper use of antibiotics leads to germicidal incidence. Understanding the pattern of germs and their antibiotic sensitivity will lead to a rational choice of antibiotics to prevent the emergence of resistance. Aim: to report the microbiological profile and sensitivity patterns in CSOM patients in our department. Materials and Methods: This is a retrospective descriptive study conducted on 45 patients from September 2019 - March 2020 at the ENT-KL Department of Dr Soetomo Surabaya Indonesia. Forty-five samples were collected from CSOM patients who underwent mastoidectomy. Specimens were collected from these patients, examination, isolation, examination and isolation antibiogram were carried out according to standard procedures. Results: A total of 45 samples were obtained from this study, and all (57.77%) of the patients were identified as CSOM cases with cholesteatoma. The number of women is 62.3% more than men, and the age group 12 to 16 (20.0%) is the most reported. There were 75.6% perforations in the tympanic membrane, and a central perforation was primarily found (35.6%). Most of the Schuller mastoid X-ray results showed sclerotic features in 29 patients (59.2%). Of the 45 ear swabs, about 68.89% of the surgical materials gave positive culture results, the remaining 31.11%. There was no microbial growth, where most of the growth of monomicrobial bacteria (57.8%). Of the isolates that grew, 70.58% were identified as the group of gram-negative bacteria, with Pseudomonas Aerogenosa isolates being the most common (44.11%). Conclusion: The sensitivity test showed the most sensitivity to Meropenam, Amikacin, Piperacillin-Tazobactam, Ceftasidim and Cefoperazone-Sulbactam Cefotaxime and Ceftriaxone showed lower sensitivity.