The present work provides reasonable understanding to the effect of radiation on body water, blood viscosity and dielectric properties (conductivity and permittivity) of different rat tissues. The characteristic frequencies (fc) of irradiated rat tissues under study decrease with increasing post-irradiation time up to 16 days for liver and kidney and up to 9 days for muscle tissues then progressively approach near non-irradiated level at 30 days post-irradiation time. The variations in body water compartments demonstrate statistically significant difference in ICW (11.61% (P= 0.0001)) or ECW...