The effect of buoyancy forces on fluid flow and heat transfer over a horizontal plate in a steady, laminar and incompressible micropolar fluid has been investigated. The wall temperature is assumed to be inversely proportional to the square root of the distance from the leading edge. The set of similarity equations has been solved numerically using the Keller-box method, and the solution is given for some values of buoyancy parameter, material (micropolar) parameter and Prandtl number. It is found that dual solutions exist up to certain negative values of buoyancy parameter (decelerated flow) for all values of micropolar parameter and Prandtl number considered in this study. Beyond these values, the solution does no longer exist. Moreover, it is found that there is no local heat transfer at the wall except in the singular point at the leading edge, although the wall temperature is different from the free stream temperature.