Novel fertilizer stabilization technologies are needed to decrease ammonia (NH 3 -N) losses and increase nitrogen use efficiency. Duromide + NBPT is a new technology that combines two molecules, Duromide and NBPT, whose propose is to increase the efficiency of the urease inhibitor NBPT in reducing NH 3 -N loss from urea. Preliminary results showed that Duromide + NBPT can be a more effective product than just NBPT, particularly under low soil pH and high-temperature conditions. This study aimed to compare the effects of urea + Duromide + NBPT, urea + NBPT, and conventional urea on soil N losses by NH 3 -N volatilization. The field experiment was conducted on a Latossolo Vermelho Distroférrico (Oxisol) in Campo Mourão, Paraná, Brazil, using a randomized complete block design with treatments arranged in a 2 × 3 factorial, comprising two N doses (45 and 90 kg ha -1 ) and three N fertilizers (urea + Duromide + NBPT, urea + NBPT, and conventional urea). The NH 3 -N volatilization data were subjected to nonlinear regression using a logistic model. The NH 3 -N losses varied according to dose and fertilizer, reaching up to 12.4 % of the applied N in the conventional urea treatment. Urea + Duromide + NBPT was more efficient than urea + NBPT in decreasing NH 3 -N volatilization. Compared to conventional urea at doses of 45 and 90 kg ha -1 of N, urea + Duromide + NBPT reduced NH 3 -N volatilization losses by 35 and 54 % and from urea + NBPT by 15 and 33 %, respectively. The new stabilizing technology Duromide + NBPT reduced NH 3 -N losses by up to 33 % compared to NBPT alone. Ammonia volatilization was influenced by soil moisture. The volatilization peak, observed after 18-19 days of N fertilizer application, was triggered by rainfall events.