Auditory thresholds of the tilapia Tilapia niloticus in a quiet water tank were investigated using a classical conditioning procedure in a stable temperature container converted into an acoustic chamber. The classical conditioning procedure followed Ishioka's method. Tilapia could hear a sound band width ranging from 100Hz to 1500Hz with maximum sensitivity 300Hz where the threshold was below 103.5dB (0dB re 1μPa). The background noise in the range of measurement frequency were in a low level of 37-47dB (0dB re 1μPa/√Hz), and signal/noise ratio in this investigation was above 50dB. Nevertheless the audiograms for tilapia from 100Hz to 1000Hz were significantly higher than in the red sea bream. It is evident that the auditory capacity of tilapia is poor, as compared to that of the red sea bream tested by the same method.