Computed axial tomography (CAT) of the brain has already proved itself to be the first line in the diagnosis of intracranial lesions. With the installation of the EMI (CT 5005) general purpose scanner at Garden City Clinic in mid-October 1977, we have been utilizing this technique not only on the cranium but on the rest of the body as well. It has proved an invaluable diagnostic tool, in that the diagnosis can often be made with this technique alone. It short-circuits many of the sophisticated routine X-ray studies which require hospitalization, an anaesthetic, and time lost to the patient and doctor. In many cases it has obviated the need for an exploratory laparotomy. In most cases the technique can be performed on outpatients; the patient is perfectly relaxed during the scan, and may be saved days in hospital. There are limitations, however, and patients should be carefully selected. A discussion of the indications for body scanning in both our own and overseas experience therefore seems in order.