Cattle ranching is one of the most important agricultural activities in Brazil. The impact of livestock on soil N 2 O emissions in Brazil has only been assessed using a Tier 1 approach of the IPCC guidelines, as there are no data available from field studies. Apart from the need for accumulating data for the development of proper direct N 2 O emission factors, we tested for possible differences between urine and dung as N 2 O sources and the difference in emissions between the dry and wet season. An area of Brachiaria brizantha at the Embrapa Rice and Bean Centre in the Cerrado (central savannah) region (Goiás state) was subdivided into plots where fresh cattle urine and dung were monitored for three consecutive periods (two in the rainy and one in the dry season) for N losses, principally N 2 O emissions and NH 3 volatilization. 15 N-labelled urine N was used in the first monitoring period for an N balance study which indicated that denitrification and NH 3 volatilization were the most important processes for N loss. Percentages of N lost as N 2 O and as volatilized NH 3 were greater for urine than for dung. In addition, N losses as N 2 O in the rainy season were much greater than during the dry season. Representing the Cerrado region and the extensive pasture systems common in this region, direct emission 0.007gN 2 O–Ng −1 (0.7%) excreta N, well below the EF 3PRP of 0.020gNg −1 (2%) used by IPCC for cattle N in excreta. The fraction of excreta N lost as NH 3 of ∼15% was in line with the IPCC guidelines. Disaggregation of emission factors for excreta type is recommended.