Over the past decade, quantitation of cardiac single-photon emission computed tomography (SPECT) data, once limited to perfusion assessment, has been extended to global and regional function assessment for both the left and the right ventricle, as well as to measurement of additional cardiac parameters of diagnostic and prognostic interest. A number of commercially available quantitative algorithms exist, based on different mathematic operators and with varying degrees of automation, that are capable of providing accurate and reproducible results. This article describes the many quantitative cardiac SPECT measurements available today, defining them in terms of validation, practical use, and limitations.