Member states closely involved in the negotiations said all the problems regarding the communist state's entry had been resolved during the talks.
This means that the chairman of the working party on Vietnam's entry can distribute a draft treaty to member states in time for its approval at the next meeting of the negotiating group on October 26, diplomats said.
If there are no last minute hitches, the treaty will then be sent for rubber-stamping by a special meeting of the 149-state WTO in early November, they added.
One diplomatic source from a country involved in the final talks said: "The negotiators' jobs are done on this one."
Vietnam, a major textiles and clothing exporter, has been negotiating entry for 12 years. It will now be able to formally join the WTO 30 days after ratifying the entry treaty.
Vietnam has already concluded bilateral accords with all WTO member states who sought them; but a final round of negotiations was needed with the full membership to ensure its trade rules and regulations were in line with WTO norms.
Talks in Geneva had focused on services and in particular on some problems that Switzerland had with maritime services.
Vietnam has one of the fast-growing economies in Asia after China, with expansion rates of over eight per cent in the last few years, and economists say that membership of the WTO will give a further boost to output.