Composite plates with cutouts are extensively used in many mechanical structures. The presence of a cutout complicates the stress distribution in the plate. In this study an attempt has been made to incorporate the effect of prebuckled stress on the stability analysis of moderately thick/very thick composite laminated plates with cutouts under in-plane compressive loading using a "Simple higher order shear deformation theory" based on four unknown displacement functions (u0, v0, wb, ws). The finite element method is employed to study the critical buckling load of laminated plates. The change in critical buckling response of both thick and thin rectangular symmetric laminates with respect to the fibre orientation angle has been studied. The interaction curves (between Nx and Ny for different parameters of the laminates) are studied in detail. © 2006 Elsevier Ltd. All rights reserved.