The aim of the present investigation is to examine the stability characteristics of laminated plates subjected to various types of in-plane loadings. Towards this, a rectangular four node finite element, having fourteen degrees of freedom per node, based on a simple higher-order shear deformation theory is developed. The theory employed herein involves four dependent variables. The element is found to be free of shear lock problems. A series of numerical problems are solved to study the effect of various parameters such as lay-up, side to thickness ratio, aspect ratio, type of loadings (uniaxial/biaxial/positive and negative shear/tension-compression/compression-tension) and boundary conditions. Some interesting observations regarding the considerable difference in the buckling resistance of angle-ply plates when subjected to positive and negative shear loading are made.