Abstract Short-wave diathermy is one of the most popular treatment modalities used to relieve pain through localized heating. In Canada its use in hospitals is as frequent as that of ultrasonic therapy devices and about 10 times more popular than microwave diathermy. Intensities of the electric and magnetic fields around applicators of 7 different diathermy units were measured at the operator position and at various untreated areas of the patient during 11 treatment regimes using 5 types of applicators. Exposure to the operator in the normal operating position, behind the device console, usually does not exceed the limits recommended by the Canadian Federal Government. The intense fields around the applicators and the cables extend up to 0.5 m and are a source of potential overexposure to the operator.