In this paper, we present a constructive method for the design of any order sliding surface using the necessary conditions for the existence of sliding surfaces for single-input affine nonlinear control systems. These conditions are a set of PDEs whose general solution will help in arriving at the sliding surfaces. The constructive design procedure is demonstrated on the cart-beam system to obtain a third-order sliding surface and on the inertia wheel pendulum system to obtain a fourth-order sliding surface. We validate the fourth-order terminal sliding mode control on inertia wheel pendulum with experimental result. © 2011 IFAC.