A multi-function probe for use in hyperthermia therapy employs at least one pair of temperature sensors, which may be thermocouples or thermistors. One sensor of the pair includes an exposed electrode which directly measures tissue temperature. The other sensor includes an electrode covered by a material having a known ultrasound absorption coefficient, for measuring the local intensity of ultrasonic energy. By comparing these two measurements, an ultrasound or other hyperthermia energy absorption coefficient of the tissue in the target region can be determined. A plurality of these paired sensors can be utilized to yield a measurement of thermal diffusion. The probe can also include one or more piezoelectric receiver elements, for providing accurate source-to-target registration.