Öz Exposing the “741” Operational-Amplifiers to gamma-rays with different dcses up to 3.5xl06 rads was shown to seriously affect their electrical characteristics. Consequently, the devices lose their main features as a results of majör defects that cause deviation in the basic behaviours of the system. The differential-mode gain and input resistance values were dropped from 185 V /mV to 70 V /mV and from 9 X106 ohm to 1.5 X106 ohm respectively.