Nitrogen availability is increasing in many aquatic systems, thus, understanding processes that affect nitrogen availability such as nitrification and denitrification is important.  Between November 2006 and January 2007, nitrification and denitrification rates were examined in two Kansas streams, Big Creek and Saline River.  Additionally, depth profiles and nutrient limitation of the processes were assessed in both streams.  Overall mean ± std. dev. nitrification rates were higher in Big Creek (0.3505 ± 0.0973 μg NO₃^--N/cm²/h) compared to those in the Saline River (below detection) (t-test, p < 0.0001).  Mean denitrification rates were similar between sites, 0.0113 ± 0.0204 and 0.0097 ± 0.0099 μg N₂O-N/cm²/h, for Big Creek and the Saline River, respectively.  Nitrification rates were highest for both sites at 8-10 cm.  Mean denitrification rates were highest at 0-2 cm for Big Creek, and 4-6 cm for the Saline River.  Nitrification in Saline River sediments was clearly limited by NH₄⁺ availability because NH₄⁺ amendments increased and glucose amendments decreased nitrification rates (ANOVA, p = 0.0022).  Nutrient limitation of nitrification in Big Creek was inconclusive; added NH₄⁺ did not significantly elevate nitrification rates over the control, but added glucose significantly decreased nitrification rates.  Denitrification in both sediments was limited by NO₃^-availability.