The article gives the organ doses for whole body CT examinations of the thoracic region, the upper abdomen, the mesogastric and pelvic regions as well as of the lumbar vertebral column and for CT scanning of the skull. The examinations were performed using an Alderson-Rando phantom with the whole body computer tomograph Somatom DR2 supplied by Siemens and with the skull computer tomograph Siretom 2000, also supplied by Siemens. It was found that the magnitude of radiation exposure of the patient depends not only on instrument-specific properties, but also to a very large measure on the examination parameters and techniques which can vary considerably from one clinic to another.