Summary--The Doppler ultrasonic flowmeter is presented as a method to help in flap outlining, transfer and return. When a directional flowmeter is added, this machine is extremely valuable for returning a flap at the earliest possible time. The Doppler is a safe, inexpensive, atraumatic, reliable instrument that can be learned in a very short time. We have found the Doppler to be very helpful in head and neck flaps.