100 cases of orbital syndromes, primary or secondary, are reviewed after CT analysis and compared with the results of plain and angiographic conventional examinations. First, the technique and normal results are described. Primary orbital syndromes (45 cases) originating in the orbit form three subgroups—tumors of the eyeball, tumors limited to the orbit and tumors of the orbit with bone lesions, with or without extra-orbital extension. Secondary orbital syndromes (55 cases) spreading to the orbit contain malignant tumors (36 cases) of which 25 are epitheliomas and benign tumors, the most frequent being meningiomas. For ocular and orbital tumors, CT allows the diagnosis of a mass and sometimes the pathological diagnosis (endocrine exophtalmos, inflammatory pseudotumors, varicose ophthalmic veins). For all other orbital tumors CT is important in determining the volume, relationships and extension, and does so better than carotid angiography or orbital phlebography. In secondary orbital syndromes, and particularly in facial malignant tumors and in meningiomas, CT is of great interest in the pretherapeutic evaluation of a tumor. It shows its volume and extension toward the face and orbital cavities, the pterygo-maxillary fossa (so important in determining the operability), the infra-temporal fossa and the endocranium, often without resorting to complementary investigational procedures which are much more aggressive. After histological diagnosis, CT allows the establishment of a therapeutic program.