The formulation of a fully compatible general quadrilateral plate bending element is described. The element is assembled from four partially constrained linear curvature compatible triangles, arranged so that no mid-side nodes occur on the external edges of the quadrilateral; thus, the resulting element has only 12 degrees of freedom. Also described is a simple shear distortion mechanism which may be incorporated into the element without changing its basic structure. Results are presented for static analyses with and without shear distortion, and for plate vibration and plate buckling studies, all performed with this quadrilateral element. It is concluded that this is the most efficient general bending element yet devised.