Two different specimens were used to investigate the effect of an overload on the number of fatigue delay cycles and the crack propagation behavior. The specimen types were the compact tension specimen (CT) and the center cracked panel specimen (CCP). Differences in the delay behavior between CT and CCP specimens were observed at high R (stress ratio) levels. For the CT specimens, the number of delay cycles increased with an increase of R ratio at the high R ratio whereas for the CCP specimens the reverse was true. The reason for the above different behavior is discussed in detail.