The complex permittivity (ε*) is composed of a real part relative dielectric constant  (ε’)  and an imaginary part  dielectric loss (ε’’).  Dielectric constant (e’) and dielectric loss (e’’) of pure groundnut oil are measured at different temperatures and frequencies. X-band microwave bench operating in the frequency range 8.2-12.4 GHz is tuned to desired constant frequency. It is observed that the dielectric constant (e’) of groundnut oil decreases with increase in temperature while the dielectric loss (e”) increases with increase in temperature. The dielectric constant (e’) of groundnut oil decreases with increase in frequency, while dielectric loss (e”) increases with increase in frequency. The dielectric constant and dielectric loss of groundnut oil samples are in good agreement with the earlier reported work.