A modification of the auscultatory blood pressure method, the phonoarteriogram, was developed. The innovated method essentially is a modified amplifying stethoscope. The pressure in the cuff is recorded from a pressure transducer, and the systolic and diastolic criteria are recorded from a microphone. The phonoarteriogram gives the advantages of a permanent record, includes pulse rate and pulse sound data, is not affected by hearing acuity, permits determinations often denied using auscultation in high ambient noise and exercise conditions, and eliminates observer bias. Three hundred and forty resting determinations and 218 exercise determinations on 60 subjects indicated good agreement between the phonoarteriogram and auscultation. In 50 systolic and diastolic intra-arterial determinations before compression of the cuff, during rest and exercise from one subject, the phonoarteriogram was as valid as auscultation. In 56 intra-arterial determinations during deflation of the cuff, i.e., simultaneous with the indirect measurements, during rest and exercise from a second subject, the phonoarteriogram was less fallible than auscultation, particularly during exercise. Phonoarteriograms are valid, reliable, and objective blood pressure record blood pressure determination; auscultatory blood pressure; intra-arterial blood pressure; physical fitness testing; ausculation; effort or physical effort; exercise; exertion; fatigue; methods, physiological; instrumentation; pulse; work Submitted on January 16, 1964