Background: The present study was conducted for evaluating Mastoid Parameters for Sexual Differentiation in a known Population. Materials & methods: A total of 50 male and 50 female subjects were enrolled. Complete demographic and clinical details of all the subjects was obtained. We analysed lateral radiographs of all the subjects. Three craniometric points were identified on the skull radiographs: (1) porion which is the uppermost point of the external acoustic meatus; (2) mastoidale which is the inferior most point of the mastoid process; and (3) asterion, which is the meeting point of three posterior skull sutures, i.e., lambdoid, occipitomastoid, and parietomastoid. All the measurements were made in Microsoft excel sheet and were subjected to statistical analysis.