Spiral CT, which consists of rapid volumetric data acquisition and planar image display, was performed on 100 children undergoing examinations of the brain and head and neck for a variety of clinical indications. The technique was evaluated for image quality and impact on clinical practice. Images of the brain were generally of diagnostic quality in infants and young children but not in older children, due to their larger heads and present X-ray tube current limitations. The lower contrast resolution demands in imaging head and neck structures permitted acquisition of high quality images in all age groups. The rapidity of the technique allowed vascular phase imaging with one-sixth to one quarter the amount of contrast medium injected routinely, reduced the number of artifacts related to patient motion and occasionally permitted scanning of young patients without sedation. As a consequence, the spiral technique appears to have the potential for improving the efficiency and safety of diagnostic CT in investigation of the brain, head and neck in children.