So-called "moyamoya" echoes identified by two-dimensional echocardiography (2 DE) in two cases with ventricular aneurysm were studied by pulsed Doppler echocardiography. The results were as follows: The flow velocity patterns in the left ventricle obtained by pulsed Doppler method were consistent with those observed by the real time 2DE method; the moyamoya echoes moved in a slow, circular fashion, and only a flow with slow velocity toward the transducer was recorded in the posterior area, whereas only a flow with slow velocity away from the transducer was recorded along the interventricular septum during cardiac cycle. The ejection flow velocity at the left ventricular outflow tract was markedly diminished. The flow velocity of the moyamoya echoes was extremely decreased and ranged between 50 and 135 mm/sec. The velocity measurements by M-mode and pulsed Doppler echocardiography gave almost the same values. Thus, the results of the present report suggest that the moyamoya echoes behave like moving blood cells, and that the source of these echoes is the sludging in the stasis of blood.