Abstract. In this article, the magneto-hydrodynamics (MHD) boundary layer ow of an Upper-Convected Maxwell (UCM) uid has been studied. The governing equations of the MHD boundary layer ow of UCM uid have been reduced to nonlinear Ordinary Di erential Equations (ODEs) by using similarity transformation. The basic idea of Optimal Homotopy Asymptotic Method (OHAM) for the nonlinear ODEs has been presented. The results obtained by OHAM have been compared with those of Homotpy Perturbation Method (HPM) and numerical Boundary Value Problem Method in order to verify accuracy of the proposed method. The e ect of the Hartman and Deborah numbers has been discussed. It has been observed that with increase in Hartman number, velocity component steadily decreases and when increasing the magnetic force, thickness of the boundary layer decreases. The obtained solutions show that OHAM is an e ective, simpler, easier, and explicit method.