The purpose of this study is to investigate the behaviour of natural convection in a wavy trapezoidal enclosure that is filled with nanofluid. The left wavy wall has wavelength, l, and amplitude, A. The top and bottom walls are adiabatic while the side walls are set to constant temperature, and shear stress occurs at the top of the enclosure. The numerical approach used in this study in order to discretize the governing equations with its boundary conditions is the finite element method where the Galerkin technique is adopted. The solutions obtained are for various values of the Marangoni number, Rayleigh number, and solid particle volume fraction. The graphs of the streamlines, isotherms, local Nusselt, and average Nusselt numbers are then presented and discussed.