Xanthan Gum has been used extensively as a viscosifier in the oil industry for different applications due to its unique rheological properties. An experimental study has been conducted to investigate the formation damage characteristics of Xanthan Gum based fluids and the results are presented in this paper.A series of core flow experiments have been conducted to investigate the possible relationship among the Xanthan Gum concentration, fluid extensional viscosity, shear viscosity, filtration loss characteristics, pressure drop across the core samples and hence, any change in the original permeability of the porous media.Results of extensional and shear viscosity measurements, API filtration loss tests, and formation damage tests conducted by using fluids of different xanthan gum concentrations are shown in this paper.