Denitrification is a key step returning nitrogen from soils to the atmosphere. The primary denitrifiers in most ecosystems are heterotrophic bacteria. Although, fungi are also known to transform nitrogen compounds, such as the production of N2O, but few studies have explored this process in soils. Aridland systems experience high temperatutres and low moisture conditions, favoring fungi in these environments. Thus, we explored the role of fungi and bacteria in denitrification of Sonoran Desert soils. In our experiment, soils were collected and incubated with biocide treatments under varying water conditions. N2O production was lower in the fungal inhibitor treatment and higher in the bacterial inhibitor treatment than in the water only control, at 30% water holding capacity (WHC). These data suggest an important role of fungi in denitrification and Nitrogen cycling in desert soils.