The Ecuadorean plaintiffs accuse Chevron of polluting land in the Amazon region for almost three decades.
Last year, an Ecuadorean court ordered Chevron to pay $19bn in damages.
Since Chevron has few assets in Ecuador, the plaintiffs are trying to get the ruling enforced abroad.
'Fraudulent ruling'
A lawyer for the Ecuadorean plaintiffs, Enrique Bruchou, said the Argentine judge had agreed to their request to freeze Chevron's assets in Argentina after they could not get the company to pay up in Ecuador.
The Ecuadorean court judgement originally ordered Chevron to pay $8.6bn in environmental damages, but that was more than doubled because the oil company did not apologise publicly.
The Ecuadorean plaintiffs say that Texaco, which merged with Chevron in 2001, dumped toxic materials in the Ecuadorean Amazon between 1964 and 1992.
Chevron says Texaco spent $40m cleaning up the area during the 1990s, and signed an agreement with Ecuador in 1998 absolving it of any further responsibility.
Chevron has in the past said the original ruling against the company was a product of "bribery and fraud" - allegations denied by the Ecuadorian plaintiffs whose lawyer has filed counterclaims of fraud against Chevron in a US court.
The company has also dismissed the plaintiffs' moves to get the ruling enforced abroad, saying that "if the plaintiffs' lawyers believed they had a legitimate judgement, they would seek to enforce it in the United States".
A judge has ordered $19bn (Â£11.9bn) of assets held by oil company Chevron to be frozen in Argentina over an environmental damages claim in Ecuador, lawyers in the case say.