A multi-input control design procedure for uncertain non-linear systems expressible in multi-input parametric-strict feedback form with suitable structural features of the uncertain control matrix is presented in this paper. The proposed procedure, based on the well-known backstepping design technique, exploits the possibility of extending, under suitable assumptions, to multi-input uncertain systems, a second order sliding mode control approach recently developed, thus reducing the computational load, as well as increasing robustness, with respect to the purely backstepping design.