Nitrogen (N) losses following land-applied animal wastes present an environmental and economical dilemma for producers. Gaseous N losses from pastureland contribute to global warming, ozone depletion, acid rain, and inefficient plant N uptake. This study was designed to monitor nitrous oxide emissions following swine waste and commercial fertilizer treatments to bermudagrass (Cynodon dactylon [L.] pers) pastures. Denitrification rates were monitored on a biweekly basis for six 0.12-ha bermudagrass pastures for three consecutive growing seasons (1998-2000). Treatments consisted of three split applications of either swine effluent supplemented with ammonium nitrate (SW) or commercial fertilizer (CF). Peak denitrification rates were greatest in 1998, ranging from 0.6 to 1.7 micro g N2O-N m-2 h-1 for effluent-treated plots and 0.3-1.5 micro g N2O-N m-2 h-1 for commercially fertilized plots. Results from this study suggest denitrification is not a significant N loss pathway in swine waste-amended bermudagrass systems.