The effects of gamma(gamma)-ray irradiation on the electrical characteristics of metal-oxide-semiconductor (MOS) capacitors were investigated. The MOS capacitor was exposed to a Co-60 gamma-radiation source with a dose rate of 0.69 kGy/h and was irradiated with gamma rays at doses up to 100 kGy. Capacitance-voltage (C-V) and conductance-voltage (G/omega-V) characteristics were analyzed before and after exposure to gamma irradiation at high frequency (1 MHz) and room temperature. These characteristics of the gamma irradiated capacitor have shown the changes in the capacitance and conductance values, respectively with gamma irradiation dose. A decrease in the C and G/omega was observed when the irradiation dose increased. Also, the capacitance and conductance curves measured at 100 kGy were corrected to decrease the effects of the series resistance (R-s). Furthermore, the values of interface states (N-ss) were determined using Hill-Coleman method. The N-ss decreases with the increasing radiation dose.