Abstract: Disclosed herein is a bio-alarm security system particularly adapted for use in banks for activating an alarm during a robbery without the need for affirmative voluntary action by an employee which might be prevented by the person committing the crime. The system includes one or more pulse rate detectors which are worn by employees, an amplifier and transmitter for transmitting the heart rate or rates to a receiving station where the heart rate signals are monitored. If abnormally fast heartbeat rates are detected such as would be caused by the stress of a robbery, an alarm is activated.