AbstractThe failure of thin, fiber‐reinforced composite laminae is considered. A parametric failure criterion applicable to plane stress loading conditions is presented. Both static and fatigue‐type loadings are treated. In general, the formulation of failure criteria for composite materials has closely followed the development of yield criteria in metal plasticity. The parametric failure criterion presented here was inspired by a general formulation recently proposed for the plastic yielding of sheet metals. The criterion satisfies the essential conditions that must be met in developing phenomenological strength criteria for composite materials. This entirely general formulation encompasses all previously proposed failure theories for fiber‐reinforced orthotropic laminae. The inherent advantages and drawbacks of the proposed parametric approach are discussed. An example of application for static loading is presented in detail. Possible extensions of the approach to fatigue‐type loading are also suggested.