A novel concept of collocation method is introduced and used for the first time to obtain a simple and accurate solution for the boundary layer in unbounded domain. Similar analysis is however not available yet in the literature. The idea is to transform the equations and boundary conditions into another set of variables and also to augment an extra boundary condition. To demonstrate the effectiveness of this ideal, we apply optimal collocation method (OCM) to find the approximate solution for the boundary layer flow of a nanofluid past a porous moving semi-infinite flat plate. The influence of pertinent parameters on the flow field characteristics is studied. The obtained results have been compared with the numerical solutions from fourth order Runge-Kutta method. The solution shows that the results of the present method are in excellent agreement with those of the numerical one. It is important that we applied OCM for the problem in unbounded domain without using Pade approximants, perturbation, linearization, small parameter or auxiliary parameter. The approach used in the present work can also be extended to different nonlinear problems in unbounded domain and the conclusion is considered useful for engineering applications involving infinity domain. (C) 2016 Elsevier B.V. All rights reserved.