Experimental investigations of the failure strength of fibre reinforced polymer matrix composite plates under compressive impact loading is presented in this paper. A split Hopkinson pressure bar (SHPB) is used to measure these properties. The specimen being a plate, its cross-sectional area is small compared with the area of the bars and the failure strength is weak. One has to then use low impedance bars made of a viscoelastic material. Subsequent experimental problems, such as dispersion corrections in viscoelastic bars, are analysed. One also has to use a special anti-buckling device to prevent the overall buckling of the specimen. It is shown that the presented SHPB system provides a precise measurement of forces and displacements at both ends of the specimen. A special attention is then given to the analysis of the test, especially in situations where a non-homogeneous state of stress in the specimen in observed.