NPN transistors and N-channel depletion metal oxide semiconductor field effect transistors (MOSFETs) were irradiated with 5 MeV protons and 60Co gamma radiation in the dose ranging from 1Mrad(Si) to 100Mrad(Si). The different electrical characteristics of the NPN transistor such as Gummel characteristics, excess base current (ΔlB), dc current gain (hFE), transconductance (gm), displacement damage factor (K) and output characteristics were studied as a function of total dose. The different electrical characteristics of N-channel MOSFETs such as threshold voltage (Vth), density of interface trapped charges (ΔNit), density of oxide trapped charges (ΔNot), transconductance (gm), mobility (μ) and drain saturation current (lDSat) were studied systematically before and after irradiation in the same dose ranges. A considerable increase in the base current (IB) and decrease in the hFE, gm and collector saturation current (lCSat) were observed after irradi-ation in the case of the NPN transistor. In the N-channel MOSFETs, the ΔNit and ΔNot were found to increase and Vth, gm, μ and IDSat were found to decrease with increase in the radiation dose. The 5 MeV proton irradiation results of both the NPN transistor and N-channel MOSFETs were compared with 60Co gamma-irradiated devices in the same dose ranges. It was observed that the degradation in 5MeV proton-irradiated devices is more when compared with the 60Co gamma-irradiated devices at higher total doses.