Twenty-three children with pulmonary stenosis were studied by means of displacement tracings taken over the right ventricle. The transducer was selected to pick up vibrations in the ultra-low frequency or palpable range. The patients were studied by cardiac catheterization and angiocardiography.Criteria previously established for normal children were applied to the patients with pulmonary stenosis. These provide a measure of the duration and relative height of the out-ward movement associated with ventricular systole.Recordings of precordial movement over the right ventricle in all of five children with severe pulmonary stenosis were abnormal by these criteria. Patients with mild pulmonary stenosis were normal in six of seven cases. An intermediate group (right ventricular peak pressures 60 to 100 mm. Hg) had abnormal records in seven of 11 instances. The “a” waveresulting from atrial contraction was exaggerated in severe pulmonary stenosis and was larger than normal in many of the mild and moderate cases.Recordings of precordial movement in pulmonary stenosis, though nonspecific in morphology, are nevertheless useful as an index of severity of the lesion, in timing phases of the cardiac cycle, in following the progress of cases before and after surgical interference, and as a method of improving appreciation of palpable phenomena at the bedside.