Chronic Suppurative Otitis Media (CSOM) with cholesteatome called unsafe CSOM because
it can cause bone destruction. Thus, it needed the diagnosis of type CSOM by using the radiological instruments. CT Scan was the gold standard in the enforcement case unsafe CSOM, but mastoid Schuller’s view was still used for areas not available CT Scan. The aim of this research was to identity the validity criteria of mastoid Schuller’s view and CT Scan. This research method used cross sectional design with the type of diagnostic test research. This
research was conducted using medical records of 63 patients enrolled CSOM ENT Department in RSPAD Gatot Soebroto term 2014-2015 that met the inclusion and exclusion criteria. The main data of mastoid Schuller’s view and CT Scan each created table 2x2 with
intraoperative findings as the reference standard. From these research obtained validity criteria mastoid Schuller’s view with a sensitivity 83,3%, spesificity 98,3%, positive predictive value 83,3% and negative predictive value 98,3%. While CT scan had a sensitivity
of 90%, specificity of 100%, 100% positive predictive value, negative predictive value of 90.9%. From this research, the sensitivity and specificity of CT Scan was better than mastoid Schuller’s view. However, mastoid Schuller’s view position had a high sensitivity and
specificity that can be used in areas that do not have CT Scan service.