"Welcome, Bienvenue, Bienvenido, Vietnam" read a giant blue banner across the across the WTO's Geneva headquarters.
Entry for Vietnam -- whose economy has grown by an average of more than 7 percent for the last decade -- comes as good news for the commerce body, which is embarking on an uncertain year while global free trade talks remain suspended and countries appear unlikely to agree on a deal.
Vietnam's entry, the terms of which were decided in November after 11 years of negotiations, opens the door to increased trade and investment in the country. It also will mean increased access to foreign markets for Vietnam's industries and a neutral arbiter to hear disputes that arise with the country's bigger, more powerful trading partners.
With a population of 84 million people, Vietnam had been the second most populous country behind Russia still outside the WTO. Russia has been seeking membership for over a decade and is probably still at least a year away.
Over the last two decades, Vietnam has gradually implemented free-market reforms, winning praise from foreign investors whose interest in the country has been growing. But the government continues to exercise direction over many large, state-owned companies.
Foreign direct investment in Vietnam reached a record $10 billion last year.