Costs of sampling grain using a diverter-type mechanical sampler were synthesized for five sampler sizes operated at six levels of annual throughput. The ranges of annual operating costs (cents per bushel) for samples in the study were: (1) 6-inch sampler, 0.0740-0.6242; (2) 9- inch sampler, 0.0591-0.7618; (3) 10-inch sampler, 0.0529-0.7618; (4) 16-inch sampler, 0.0157-0.0439; and (5) 36-inch sampler, 0.0073-0.0602. These cost data will allow grain industry decisionmakers to analyze the costs against expected benefits of adopting the warehouseman's sample-lot inspection service of the U.S. Department of Agriculture. Widespread adoption of the warehouseman's sample-lot inspection of grain which utilizes the diverter-type mechanical sampler would contribute significantly to railcar utilization, and consequently to increased efficiency throughout the grain marketing-transportation complex.