The complex dielectric constants at room temperature of various goat tissues (liver, muscle, kidney, heart and brain) were measured in the frequency range 1 to 10 GHz with the help of a HP Network Analyser HP 8510A. Open ended coaxial cable method was employed for the measurement. The system imperfections are completely avoided by calibrating the system with four known materials and their reflection coefficients were used in the calculation along with the reflection coefficient of the sample. The relaxation frequency in the δ region, spread of relaxation, volume fraction of protein present in tissues are calculated from the measured dielectric data. © 2005 IEEE.