Three patients with intermittent exophthalmos were studied by computed tomography (CT) and colour-coded Doppler sonography (CCDS). By CT the possible diagnosis of an orbital varix was established. CCDS, however, with the dynamic evaluation and realtime direct imaging of flow and the possibility of examination in different positions facilitated the diagnosis of this orbital vascular disorder without the need for any contrast material. This technique may prove to be a useful adjunct to computed tomography for the evaluation of suspected vascular lesions of the orbit. Surgery confirmed the diagnosis in all patients.