Rates of NO3-disappearance under anaerobic conditions, from six widely differing soils, gradually increased and then became relatively constant when glucose was added in increments supplying 0.04 to 1.5 mg of C/g of soil. Maximum rates of NO3-loss ranged from approximately 9.3 to 13.7 percent/hr. Increased production of NH4+accompanied glucose additions in all soils. Results based on13N-labeled Ca(NO3)2showed that substantial amounts of NO3-were reduced to NH4+after 4 hr of anaerobic incubation, and15NH4+continued to increase until all or most of the15NO3-had been converted to NH4+, organic N, and gaseous forms (N2and N2O). Results seriously challenge the prevalent view that denitrification accounts for essentially all NO3-dissimilation in anaerobic soils.