Dumping is when an exporting country sells their goods in the foreign market for less than the price of the goods in their own domestic market. Dumping has a negative connotation because it threatens domestic industries in the importing country. In response to harmful dumping situations, mechanisms of defense have been developed to protect nations from unfair trade practices. The General Agreement on Tariffs and Trade (GATT) recognizes in Article VI anti-dumping tariffs as a legitimate defense to protect domestic industries from foreign predatory pricing practices. This paper focuses on anti-dumping developments in international trade since the beginning of the 20th century until the creation of the World Trade Organization (WTO), and pays special attention to those in Brazil and the United States.