Technical Abstract: It is often assumed that displacement of native perennial vegetation by exotic annuals will alter nutrient cycling. We compared nitrogen dynamics of native bunchgrass vegetation and adjacent stands of the exotic annual grass Bromus tectorum on three sites in southeastern Washington, USA. The stands of B. tectorum had dominated the sites for at least 40 years. We want to emphasize that these sites were not prone to frequent wildfires as can be the case in some B. tectorum dominated ecosystems. Over a two-year period we found very few consistent differences between the two vegetation types in aboveground standing crop, root mass, in situ N mineralization, extractable soil N, or total soil C or N. B. tectorum aboveground plant mass and litter tended to have lower C/N ratios than did the native vegetation, but the results were not consistent over time or site. It appears that the exotic annual adapted to the resources on the site and at least at the fairly gross level we measured, had little impact on soil nitrogen. Our results suggest that caution must be used in assuming that a change in vegetation type and growth form will necessarily alter soil N levels.