Abstract: Disclosed is an ultrasonic probe for use in medical diagnostic systems for examination within a human body. The ultrasonic probe comprises an array of transducer elements for transmission of ultrasonic wave into an examined body and for reception of echo waves returning from the examined body. Further included in the ultrasonic probe is an ultrasonic propagation medium which is provided between the transducer element array and the examined body. The ultrasonic propagation medium is made of a synthetic rubber having an acoustic impedance close to that of the examined body and having a low acoustic attenuation coefficient. Preferably, the synthetic rubber is one of butadiene rubber, butadiene-styrene rubber, ethylene-propylene rubber, and acrylic rubber.