The bending responses of porous functionally graded (FG) single-layered and sandwich thick rectangular plates are investigated according to a quasi-3D shear deformation theory. Both the effect of shear strain and normal deformation are included in the present theory and so it does not need any shear correction factor. The equilibrium equations according to the porous FG single-layered and sandwich plates are derived. The solution of the problem is derived by using Navier’s technique. Numerical results have been reported, and compared with those available in the open literature for non-porous single-layered and sandwich plates. Effects of the exponent graded and porosity factors are investigated.