Classical oscillometry was used to determine indirect systolic/diastolic blood pressure in nine newborn infants. The measurement was facilitated by a relatively simple and inexpensive electronic oscillometer, the construction of which is described. Comparisons between indirect leg and direct intra-aortic blood pressure revealed a systolic difference of 0 to 5 mm Hg and a diastolic difference of 0 to 10 mm Hg, depending on respiratory variations and accuracy of calibration.