The anatomy of the rat cavernous sinus has been reported inconsistently in the literature. In the present study, we aimed to investigate the rat cavernous sinus and surrounding venous channels using radiological methods. Four adult Sprague Dawley rats underwent computed tomography venography following the injection of a contrast agent via the tail vein. In all rats, the cavernous sinus was consistently identified laterally adjacent to the internal carotid arteries and pituitary glands. Intracranially, the cavernous sinus extended along the floor of the skull base, from the orbito-rotundum foramen to the posterior edge of the basisphenoid. It had inferior continuity with the interpterygoid veins via the midline osseous venous component, anterior continuity with the superior and inferior orbital veins, superior continuity with the basal vein, and posterior continuity with the superior and inferior petrosal sinuses. Our findings were generally consistent across all rats, although minor variations in tributaries were noted. The present findings update our anatomical understanding of the cavernous sinus in rats and potentially resolve inconsistencies from past reports. Furthermore, we have provided a detailed radiological visualization of the cavernous sinus and its surrounding venous structures through computed tomography venography, which may serve as an atlas of venous anatomy in this region. This improved understanding will aid in the interpretation of in vivo rat studies involving the cavernous sinus, and will contribute to the field of comparative neuroanatomy.