The classical laminate theory is generalized for a case when layers contain damage in form of intralaminar cracks. The homogenized constitutive relationships for damaged laminate have a similar form as in the classical theory of not damaged laminates. Closed form expressions for extensional stiffness matrix are derived. Apart from elastic properties of layers they contain only laminate geometrical parameters and average relative displacements of crack surfaces. Simple power law type of formulas for these quantities, obtained using FEM based parametric analysis render accurate predictions for the elastic properties degradation of laminates.