Distributions of the wall temperature, the Nusselt number, and the friction coefficient on all of the bounding walls of laminar three-dimensional forced convection flow adjacent to backward-facing step in a rectangular duct are reported. A uniform heat flux is imposed on the bounding walls (stepped wall, sidewalls, and flat wall) downstream from the step, while the walls of the duct upstream from the step and the step are treated as adiabatic surfaces. The flow upstream of the step is treated as hydrodynamically fully developed and isothermal, and the outlet flow downstream from the step is treated as being hydrodynamically and thermally fully developed. Local and average results are presented for a Reynolds numbers range of 150-450, and some results are compared with their equivalent from the two-dimensional case. (C) 2004 Elsevier Ltd. All rights reserved.