The boundary-layer equations for combined forced- and free-convective flow over flat plates have been numerically solved using a simple implicit finite-difference scheme. The method of analysis has been developed for flow over plates for which either the surface temperature distribution or the surface heat-flux distribution is arbitrarily specified. Both assisting flow, in which the longitudinal component of the buoyancy force is in the same direction as the forced flow, and opposing flow, in which it is opposite in direction to the forced flow, have been considered. Numerical results have been obtained for plates having a uniform temperature and a uniform heat-flux distribution, and for fluids with Prandtl numbers of 0.7, 3, and 10.