Fretting fatigue crack initiation behavior of titanium alloy, Ti-6Al-4V was investigated by using different geometries of the fretting pad. Specimens were examined to determine the crack initiation location and the crack angle orientation along the contact surface. Fretting fatigue experiments were analyzed with the finite element analysis. Several critical plane based parameters were used to predict the number of cycles to fretting fatigue crack initiation, crack initiation location and crack orientation angle along the contact surface. These predictions were compared with the experimental counterparts to study the role of normal and shear stresses on the critical plane in order to characterize fretting fatigue crack initiation behavior. From these comparisons, the fretting fatigue crack initiation mechanism in the tested titanium alloy appears to be governed by the shear stress on the critical plane. However, the role of normal stress on the critical plane at present appears to be unclear.