A study into the performance of CSM (Chopped Strand Mat) reinforced polyester laminates subject to low velocity impact at oblique angles is presented. The investigation encompasses both an experimental and theoretical assessment of the impact event, viz damage tolerance and residual material properties of flat, clamped composite plates. A short introduction is followed by a comprehensive review of the most relevant published literature on all aspects of impact induced damage. A theoretical analysis based on the use of damage toughness parameters is formulated to predict the residual tensile strength and stiffness properties of impact damaged plates. The analysis is further extended to determine the total internal stress distribution in the system. A combination of Hertzian contact, plate bending and finite element solution are used to establish the influence of plate inclination on the resulting stress state. Several common failure criteria were used to predict the extent of the damage. These predictions are compared with experimental data. Results from an extensive experimental programme are presented A fully instrumented test rig was used to assess the influence of imparted energy, impact force, and plate indentation with respect to surface indentation profiles, damage areas and micrographic evidence. The theoretical and experimental results are graphically presented, discussed in detail and exhibit good agreement. The study is finally concluded with comments summarising the most pertinent points derived from the present investigation together with recommendations for further work.