This book is devoted to the development and formulation of an improved theory of anisotropic plates free from the basic hypothesis of the classical theory, i.e., from the hypothesis of nondeformable normals. The versions of the improved theory considered in this book are, in fact, new approaches for the consideration of the effect of transverse displacements and of normal stresses with respect to the middle-plate surface. These versions introduce a basic correction to the classical theory and may be applied in the derivation of the first correction to the basic stress state of the classical theory. The magnitude of this correction increases together with the ratio Ei/Gi3 and may be significant for highly anisotropic plates.