The central themes to be addressed during the Doha Round of world trade negotiations are the reduction of the agricultural production and export subsidies, and improved market access for agricultural and non-agricultural goods. The G-20 group wields enough power to press negotiations at the Doha Round toward lower agricultural trade barriers and production and exports subsidies. The objective of this study is to determine the impacts of four possible Doha Round scenarios on the economies of Brazil, China, and India. The scenarios are examined using the Global Trade Analysis Project’s (GTAP) general equilibrium model and database. Scenarios focusing on the reduction of agricultural production and export subsidies are studied. The scenarios are then analyzed taking into account implementation of the Harbinson approach and the Swiss formula to tariff reduction. The best results obtained by Brazil, China, and India are those from the Scenario 4. In this scenario, WTO recommendations for agricultural production and export subsidies reduction are simulated and, at the same time, the Girard formula is applied to reduce agricultural import tariff and an average tariff cut is applied to manufactured products. Changes in GDP growth rate, in the per capita utility, and in the equivalent variation are higher under this scenario for Brazil, China, and India. The losses, due to low competitivity, by the EU15 and the US in the agricultural products in all analyzed scenarios are making it difficult to reach an agreement at the Doha Round of negotiations.