Pulmonary angiography is considered the definite method of diagnosing pulmonary emboli. It is hypothesized that pulmonary cineangiography is superior to conventional pulmonary angiography for quantitation of pulmonary emboli. The present study was undertaken to test the hypothesis. Six patients with an age range from 27 to 70 years with documented pulmonary emboli by pulmonary angiogram, had pulmonary cineangiograms. Pulmonary angiogram defined pulmonary emboli in nine major vessels in the six patients; while, pulmonary cineangiogram revealed another 10 major vessels with pulmonary emboli, which were either not detected or considered equivocal by the conventional pulmonary angiography. The pulmonary embolic score as an index of the extent of pulmonary emboli was 24 (mean 4 +/- 2.52 1SD) by the conventional pulmonary angiography, while the score was 60 (mean 10 +/- 3.22 1SD) by the pulmonary cineangiography, P less than 0.2. Thus, in cases with pulmonary emboli, pulmonary cineangiogram is superior to conventional pulmonary angiogram for the quantitation of pulmonary emboli.