In this paper, the development of a multiaxial fatigue failure criterion is shown, and as an application of the above criterion, a fatigue analysis of a crankcase is conducted. The octahedral shear stress amplitude and the peak value of the maximum principal stress are used in this criterion. The accuracy of the criterion is validated by tension-torsion biaxial fatigue tests. Furthermore, fatigue failure prediction of a crankcase is carried out using static analysis and the criterion. The combination of the static analysis and the criterion enable the prediction of fatigue failure.