This paper presents a perturbation solution for flow in a porous saturated channel bounded by two isothermal parallel plates. It is considered that the flow is affected by an internal source term which is to be heated or cooled. The Brinkman flow model is employed to find fully developed velocity distribution. This solution permits a uniform solution for the energy equation to find the temperature distribution as well as the Nusselt number. The results found here are also valid for hyperporous materials which are of current practical importance.