It has been well established that watershed development causes dramatic changes in the geomorphology, hydrology and biological communities of receiving stream ecosystems.  The effects of urbanization on stream biogeochemical dynamics have been less studied to date and appear to be less consistent.  We compared carbon (C) and nitrogen (N) dynamics from sediments collected from streams draining five urban and three forested catchments within the NC piedmont.  Despite much higher water column DOC concentrations and bioavailability and higher N concentrations in the urban streams we detected no differences in benthic organic matter concentrations or C mineralization rates between urban and forested stream sediments.  In contrast, rates of N processing differed between the urban and forested streams, with potential rates of both nitrification and denitrification reduced in urban stream sediments. Preliminary analyses suggest that the community composition of denitrifying microbes in these sediments is distinct between urban and forested watershed streams.  We will discuss possible controls on microbially mediated nitrogen cycling in these urban streams by comparing annual and storm hydrographs and sediment metal concentrations and between the urban and forested streams.