<p>The anatomical position of the sigmoid sinus influences the extent of mastoid pneumatization. The existing literature shows conflicting observations on the relation of the sigmoid sinus with the extent of mastoid pneumatization. Understanding the anatomy of the sigmoid sinus and its variations is crucial for any otolaryngologist. On HRCT temporal bone, the sigmoid sinus appears to form a shallow indentation on the posterior surface of the mastoid. Radiologists often use the sigmoid sinus as a reference point to assess the degree of mastoid pneumatization. This study was executed utilizing six anatomical landmarks within the temporal bone. To study the relation of the sigmoid sinus with mastoid pneumatization in various middle ear pathologies. Patients who presented to ENT OPD with ear-related complaints requiring imaging to confirm the diagnosis or as a pre-operative work-up were referred to the department of radiology for HRCT temporal bone scan. Scans were divided based on the type of mastoid pneumatization into three types. The scans were systematically categorized as: hyper-pneumatized (19 scans, 37.25%), moderately pneumatized (17 scans, 33.33%), and hypo-pneumatized (15 scans, 29.41%). The mean distance between the incudo-malleolar joint and the sigmoid sinus showed statistically significant results when compared for different pneumatization status of the temporal bone. HRCT temporal bone can be useful to study the variations in the usual anatomy of the sigmoid sinus, enabling the surgeon to effectively strategize the surgical approach pre-operatively, hence minimizing the risk of intra-operative difficulties arising from atypical anatomy or positioning of the sigmoid sinus.</p>