In this investigation, exact displacement functions were used to analyze thick anisotropic rectangular plates of two boundary conditions; simply supported on all edges (SSSS) and clamped on all edges (CCCC). Third order shear deformation model was employed in the formulation of the total potential energy functional for thick anisotropic rectangular plate. This total potential energy functional was reduced to the governing equation and compatibility equations for thick anisotropic plate. The governing equation and compatibility equations were solved to obtain the general displacement functions. By satisfying the boundary conditions for SSSS and CCCC plates their distinct displacement functions were obtained. These displacement functions were used to obtain the stiffness coefficients (k-values) for the plates. Minimizing the total potential energy functional with respect to the coefficients of the displacement functions gives the formulas for calculating the values of the coefficients. At this point, the displacements and stresses of the plates were calculated at various angles fiber orientations (0^0, 〖15〗^0, 〖30〗^0, 〖45〗^0, 〖60〗^0, 〖75〗^0 and 〖90〗^0) and various span-to-thickness ratios, α (5, 10, 20, 30, 40, 50, 60, 70, 80, 90 and 100). The results obtained were close to the results of other scholars.