Total fatigue lives of notched structural components are considered as a summation of crack initiation and propagation phases and a two-phase approach to fatigue life prediction is presented. The local strain approach and fracture mechanics-based approach are used to predict the lives spent in the two phases. A strain-life curve corresponding to the transition crack size where the two phases are divided is formulated based on the equivalence between the Coffin-Manson law and a simple Elastic-Plastic Fracture Mechanics crack growth law in the low cycle fatigue regime. A crack growth model that includes the short crack behaviour is used to predict the crack propagation life. The transition crack size, related to the average grain size of the material, is chosen in such a way that the proposed approach can be appropriately adopted in both phases, considering the stress gradient and microstructure effects. The proposed approach is applied to predict fatigue lives of various notched specimens. The three-dimensional effect is considered in the assessment. The predictions are in good agreement with the experimental results.