Technical Abstract: Japanese brome (Bromus japonicus Thunb.) has invaded many hectares of Northern Great Plains rangelands. We studied the effect of Japanese brome on current-year's standing crop of a western wheatgrass [Pascopyrum smithii Rydb. (Love)] dominated plant community in the Northern Great Plains. Brome seedlings were either removed from or left in replicated 1-m**2 plots. Standing crop was sampled near peak production in 0.25 m**2 plots centrally located in each 1 m**2 plot. In analyzing data, effects of study site and year were combined to form blocks (n=6). Standing crop of western wheatgrass increased (891 to 1,095 kg ha**-1), but total standing crop (1,873 to 1,334 kg ha**-1) decreased with brome removal (708 to 12 kg ha**-1). Increased western wheatgrass standing crop resulted from increased tiller density and not weight per tiller. A non-significant block by brome removal interaction for western wheatgrass standing crop (P=0.90) suggests these results can be expected over a wide array of environmental conditions with variable April to late June or mid July precipitation (101 to 382 mm) and variations in total current year standing crop (1,260 to 2,538 kg ha**-1) containing varying percents of annual brome (22 to 51%), western wheatgrass (35 to 63%), and other species (4 to 35%).