A procedure for gated single-photon emission transaxial tomography of the cardiac blood pool using a commercially available rotating camera and a computer is described. During image acquisition, the end-diastolic and end-systolic frames are retained after each of the 16 angular steps of the rotation of the camera around the anterior side of the patient's chest. Complete acquisition takes 25 minutes; 10 more minutes are required for the reconstruction and processing of the sections. One set of images is oriented transaxially; the other set includes vertical sections obtained by rotation around a vertical axis passing through the center of the left ventricular cavity. Results from the planar and tomographic examinations were in good agreement for most of the 18 patients who underwent both studies, although more inferior abnormalities were detected with tomography.