The current study investigates the effect of foreign object damage (FOD) on the preexisting compressive residual stress field associated with laser shock peening (LSP) and its evolution upon combined LCF/HCF cycling. FOD was introduced onto an aerofoil-shaped specimen that had been previously LSP treated through ballistic impacts at angles of 0 degrees and 45 degrees to the leading edge. It is shown that the FOD notch created by 45 degrees impact was asymmetric in shape and smaller in depth compared to that created at 0 degrees impact. Significant through thickness compression was introduced parallel to the leading edge as a result of the LSP process. The residual strain distribution was mapped around the FOD notch by synchrotron X-ray radiation. The results show predominantly compressive stresses ahead of the notch, being greater for the 0 degrees compared to 45 degrees impact. No significant stress relaxation was observed after a combined (1000 HCF cycles superimposed on 1 LCF cycle) cycle. ; Times Cited: 0 5th International Conference on Mechanical Stress Evaluation by Neutrons and Synchrotron Radiation Nov 10-12, 2009 Mito, JAPAN Japan Atom Energy Agency; Ibaraki Univ