Unicon Physics Inc. has developed an effective quality assurance program to meet the demands of JCAHO in Diagnostic Ultrasound. Several parameters determine the imaging performance of an ultrasound unit. They include axial and lateral spatial resolution, accuracy of distance with range, depth of the dead zone, contrast sensitivity, sensitivity and dynamic range and TGC operation. In order to enhance system performance, high intensity levels of ultrasound can be used with possible bioeffect of potential heating of tissues. For imaging purposes the threshold to observe this bioeffect is way above the normal expected clinical range. Equipment performance for accuracy and safety within the specified tolerances can be ensured by timely and periodic quality control measurements.