A calculational benchmark of neutron transport through a slab of iron is based on a rigorous Monte Carlo treatment of ENDF/B-IV and ENDF/B-V cross sections. The model consists of 2-, 14-, and 40-MeV neutrons incident on a 3-m infinite slab. This benchmark problem can be used to validate multigroup cross-section libraries and the associated multigroup transport codes. Plots and tables of the data show the spatial and energy distribution of neutrons for monoenergetic normally incident sources.