The present study is concerned with the reflection and transmission of plane waves at an imperfect interface between two different fluid saturated porous half spaces. The expression for the reflection and transmission coefficients which are the ratios of the amplitude of reflected and transmitted waves to the amplitude of incident waves are obtained for an imperfect boundary and deduced for normal stiffness, transverse stiffness. The variations of amplitude ratios with angle of incidence are depicted graphically. A particular case of reflection at the free surface in fluid saturated porous half spaces has been deduced and discussed. A special case of interest has also been deduced from the present investigation. It is found that amplitude ratios of the reflected and transmitted waves are affected by the stiffness of the media.