Ultrasonography is a relatively cheap and effective way to screen for orbital disease (tumors), and is useful in deciding when to request other types of radiological tests. It is not a technique that allows a high degree of accurate diagnosis where orbital tumors are concerned, except in a few cases where the ultrasonographic findings are typical. Ultrasonography also allows the measurement of orbital tumors when following patients with benign tumors such as cavernous hemangiomas, and therefore avoids more expensive and invasive tests. It is the best modality when assessing extraocular muscle thickness and changes in thickness. Effective ultrasonography requires an experienced operator to give the best clinical results. Deep orbital lesions cannot be reliably assessed by ultrasonography using safe energy levels. Reviewing a range of clinical conditions and comparing the ultrasound findings with other imaging techniques and histopathological findings after surgery allows the clinician to develop a more reliable base of knowledge.