Nitrous oxide (N2O) emission estimates are important to ascertain the greenhouse gas balance of ethanol produced from sugarcane. We quantified N2O emissions in the presence of sugarcane crop residues, N fertilizer (ammonium sulfate), and a nitrification inhibitor (NI, dicyandiamide). Two field experiments were conducted to evaluate the implications of N fertilizer application during dry and wet seasons at two locations in southeast Brazil. Treatments consisted of four levels of crop residue (0, 5, 10, and 15 Mg ha(-1)) and three of N fertilizer (0 and 120 kg ha(-1) and 120 kg ha(-1) plus NI). N2O emission was measured using the closed chamber method and sugarcane yield via mechanical harvest. N2O emissions were higher in wet than in dry seasons following N fertilizer application, albeit affected by crop residue and NI in both. Retaining crop residues on the soil increased N2O emission and sugarcane yield. The N2O emission factor from N fertilizer ranged from 0.12% to 1.44% of N applied. NI reduced N2O emissions (by 87% and 63% in dry and wet seasons, respectively). Sugarcane yield varied from 42 to 92 Mg ha(-1) of fresh matter stalk and emission intensity from 3.7 to 22.9 kg of CO2eq, Mg of stalk(-1). The lowest greenhouse gas intensity was recorded with 5 Mg ha(-1) crop residue and 120 kg ha(-1) N supplemented with NI. Therefore, partial crop residue removal and NI addition to N fertilizer may be effective strategies to improve the sustainability index of biofuel from sugarcane and reduce N2O emissions and intensity.