Brazilian corn production has an expressive participation in world trade stage. Agribusiness has been growing and gaining an important position for economy in Brazil. The Brazilian corn harvest for 2017–2018 was 82 million tons, placing Brazil as the third largest global producer behind China and the United States. This study compares four south and southeast Brazilian corn exportation ports according to their operations, infrastructure and geographic position. A multicriteria decision tree was established and, with the analytical hierarchy process (AHP) tool, an informational database, and considering expert opinions about the gathered data, we were able to determine which ports are the better choices for corn exportation. Surprisingly, Rio Grande took a better place than Paranaguá’s port. Its operations and infrastructure nodes have the same weight in terms of decision making. However, a port’s geographical position has a very weak decision-make importance. Furthermore, Rio Grande is almost three times better than Paranaguá in Water Depth and this made Rio Grande beat Paranaguá from an infrastructure point of view. So, the operations node was the point to pay attention to, and this is the main reason for Rio Grande’s position.