One of the objectives of our study was to determine the changes in N₂O emissions in two contrasting soils, after the application of urea or coated urea. Coated urea is a new attempt to reduce soil N₂O emissions. However, there is evidence that the reduction of N₂O emissions due to coated urea strongly depends on the used soil type. We hypothesized that changes in nitrification and/or denitrification rates after fertilizer application can explain the difference in N₂O emissions from coated urea in different soils. Thus nitrification and denitrification rates were determined using a 15N tracer technique at 3 timings, before, 1 week and 1 month after fertilizer application. By using coated urea on Andosol a reduction of N₂O emissions of around 30% could be achieved, however, in Fluvisol no significant decrease was observed. For Fluvisol nitrification as well as denitrification contributed equally to N₂O emissions when urea was applied whereas the contribution of nitrification to N₂O production was enhanced only when coated urea was applied. Thus, the efficiency of coated urea with regards to N₂O production is depending on the soil type and the magnitude of the enhancement of soil processes (nitrification and denitrification) determined this efficiency.