M-Mode echocardiogram is short form for Time-Motion Mode echocardiography. It was one of the earliest modes of echocardiography. There was also a B-Mode or brightness mode along with it. Newer modalities like 2-D, 3-D, Doppler, colour Doppler and tissue Doppler have relegated M-Mode to limited use in the left ventricular measurements alone. But it had a higher use in mitral stenosis and pulmonary hypertension prior to the Doppler era. Important M-Mode findings are still worth learning.