Computerised Tomography has revolutionised the approach to many problems, especially orbital diseases. It is a simple, safe, non-invasive diagnostic examination done on an out patient. Computerised Tomography not only shows the presence of a lesion but also shows the extent of the disease and its relationship to other intraorbital and adjacent structures. With coronal scans, relationship of orbital disease to the optic nerve and extraocular muscles can be well demonstrated. However it must be remembered that Computerised Tomography is not a microscope to give histopathological diagnosis but we can often draw a conclusion of the nature of the disease by Computerised′ Tomography appearances and clinical details. Now Computerised Tomography has become the primary investigation of choice in evaluating orbital disease.