New heart imaging methods, including echocardiography, single-photon emission computed tomography (SPECT) and nuclear magnetic resonance, involve measurements of left ventricular (LV) wall thickness in cross sections perpendicular to the LV long axis. To provide a reference base, LV myocardial wall thicknesses were measured in human autopsy specimens. Short-axis views were chosen at the base of the heart, at the level of the papillary muscles and at a level close to the apex. At the 3 levels, LV wall thicknesses were measured for each of 36 circumferential sectors. The measurements revealed a nonuniformity of LV myocardial wall thickness, related to the papillary muscles, the anterior and posterior junctions with the right ventricle and the thinness of the ventricular septum. These findings help to explain the structured appearance of SPECT 201-thallium short-axis views.