In this study, we obtained a new numerical solution for the MHD peristaltic flow of a bio-fluid with variable viscosity in a circular cylindrical tube via the homotopy perturbation method (HPM). The axial velocity is obtained in a closed form. We made comparison between the results obtained by only three terms of HPM series with those obtained previously by perturbation technique. We observe that only few terms of the series expansion are required to obtain the numerical solution with good accuracy. Copyright (C) 2010 John Wiley & Sons, Ltd.