Historically, the vast majority of cropland in the western Great Plains was either seeded to continuous monoculture wheat or was in a wheat-fallow rotation. The objective of this paper is to determine the combined effects of crop diversity and tillage systems on wheat grain yield and net returns for farms in the traditional wheat region of the western Great Plains. Farm level data were obtained for four crop production seasons. Crop diversity was relatively more important to system economics than the type of tillage used. Net returns per acre were greater on farms that included a diversified cropping system.