Computed tomography (CT) was used to investigate orbital tumors in 3 dogs. Tumors were clearly defined on transverse CT scans by their inherent density and gross distortion of normal orbital anatomy. Dorsal images synthesized from the original transverse scans were also used to visualize size and extent of tumors. Use of an iodinated contrast medium did not appear to improve localization of tumors in the orbit but was useful for identification of tumor extension into the calvaria. It was concluded that CT offered advantages over existing methods of radiographic diagnosis of orbital tumors and exophthalmos.