Argentina broke global trade rules by imposing a raft of hurdles for goods sold by partners including United States, the EU and Japan, a WTO disputes panel ruled on Friday.
In the ruling, the World Trade Organization's watchdog arm said that Buenos Aires should "bring the inconsistent measures into conformity with its obligations" under international rules.
Washington hailed the decision.
"This is a major victory for American workers, manufacturers and farmers," US trade chief Michael Froman said in a statement.
"Argentina's protectionist measures impact a broad segment of US exports, potentially affecting billions of dollars in US exports each year," he added.
Froman's European Union counterpart, Karel De Gucht, was equally upbeat.
"I've made standing up to protectionism one of the hallmarks of my term as EU Trade Commissioner. This case sends an important signal that protectionism is not acceptable," he said in a statement.
"I call on Argentina to move quickly to comply with the ruling of the WTO panel and remove these illegal measures and open the way for EU goods to compete fairly on the Argentinian market," he added.
The WTO panel of trade and legal experts was set up in May 2013 to hear complaints filed by Washington, Brussels and Tokyo, which claimed that Argentina was not playing fair.
In their sights were import licencing rules, which among other things require firms eager to export to the country to import Argentinian goods in exchange.
One of the most well-known examples was German car maker Porsche, which was forced to commit to purchasing Argentinian wine and olive oil in order to get roughly 100 of its cars into the country.
Other contested areas included limiting imports in volume or value, ordering trade partners to make investments in Argentina and to refrain from repatriating profits from Argentina.
The WTO polices global trade accords in an effort to provide its 160 member economies with a level playing field.
Wrangling over import measures is common at the WTO, whose panels can authorise retaliatory trade measures against a guilty party that fails to fall into line.
Argentina still has the option of appealing against the ruling.
The WTO disputes settlement process can last for years, amid appeals, counter-appeals and compliance assessments.