An efficient elastic-plastic finite element procedure to analyze crack closure and its effects on fatigue crack growth under general spectrum loading is presented. A hybrid-displacement finite element procedure is used to treat properly the stress and strain singularities near the crack tip; and crack growth under cyclic loading is simulated by the translation of certain “core” elements, near the crack tip, in which proper stress and strain singularities were embedded. Both pure mode I and mode II types of cyclic loading are considered. In the mode I case, four types of cyclic loadings, i.e., constant amplitude block loading, high-to-low block loading, low-tohigh block, and a single overload in an otherwise constant amplitude block loading, are considered. The stress level at which crack growth occurs is selected on the basis of experimental results reported in literature. In the case of mode II, only a constant amplitude block loading is considered. Detailed results are presented for crack closure and opening stresses, crack surface deformation profiles, etc., in each case. Certain observations, based on the present numerical results, concerning various factors that cause crack-growth acceleration or retardation under general spectrum loading are presented and discussed.