The influence of fixation time on the ultrasound damping was investigated in vitro in both normal and altered formalin-fixed testicular tissue. By means of ultrasound spectroscopy the ultrasound damping coefficient alpha is estimated. The results of measurements in different time intervals after onset of fixation did show that in both normal and altered testicular tissue only slight changes of ultrasound damping was found. Therefore, the influence of fixation time could be neglected.