Abstract: An apparatus and method is disclosed for automatically determining the pulse rate and systolic and diastolic blood pressure. The apparatus comprises a device for detecting arterial pulsations in a subject's body. The improvement comprising a sensor in a pressurized bladder and responsive to arterially induced pressure pulsations. The sensor comprises a pressure transducer chamber and a pressure transducer. The pressure transducer chamber contains a pressure equalization passageway communicating with the interior of the bladder and the interior of the pressure transducer chamber. The pressure equalization passageway equalizes the pressure between the bladder and the chamber to prevent the pressure in the bladder from impending upon the pressure transducer. A method is disclosed for automatically determining pulse rate and systolic and diastolic blood pressure.