<p>We present here a review of the literature on the human cochlear aqueduct. The review describes the anatomy of the cochlear aqueduct as investigated using high-resolution computed tomography of the temporal bones, presents methods for assessing the size of the cochlear aqueduct, describes types of cochlear aqueducts, and discusses reasons for the occasional non-visualization of the cochlear aqueduct on computed tomograms. The criteria for and validity of the concepts of “wide” and “narrow” cochlear aqueducts, the patency of the cochlear aqueduct and its changes with age, and the role of the cochlear aqueduct in the development of purulent inflammation in the structures of the labyrinth of the inner ear, perilymphatic hypertension, and temporary perilymphatic hypotension are analyzed. Published data show that anatomically and functionally wide, or more precisely, excessively permeable, cochlear aqueducts can occur. Pathological conditions of the cochlear aqueduct and its interaction with adjacent anatomical structures are discussed. A clinical case of unilateral fluctuating hearing loss is presented, in which a congenital anomaly of inner ear development was detected on a computed tomography scan i.e., dehiscence between an anomalously large bulb of the jugular vein and the cochlear aqueduct. Assessment of the contribution of the aqueduct to the pathology of the inner ear requires more attention to be paid to this anatomical structure, and further accumulation of data is required.</p>