The main objective of this study is to establish fatigue crack initiation and growth behavior of a powder metallurgy 2124 aluminum alloy-SiC whisker composite. Cyclic compressive loading was adopted for the fatigue experiments using compact tension type specimens. The effect of compressive overload in terms of ΔK variation was also examined. Fatigue crack initiation was found to occur easily for a given ΔK, but its crack length was saturated quickly. Following an overload, the saturation crack length increased again with increasing ΔK. The results provide a basis for the development of rational method to control fatigue crack length following a compressive overload.