U.S. District Judge Nina Gershon issued the preliminary injunction against the government, saying it's in the public's interest for the organization to continue receiving federal funding.
ACORN claimed in its lawsuit that Congress' decision to cut off its funding was unconstitutional because it punitively targeted an individual organization.
Gershon said in her ruling that ACORN had raised a "fundamental issue of separation of powers. They have been singled out by Congress for punishment that directly and immediately affects their ability to continue to obtain federal funding, in the absence of any judicial, or even administrative, process adjudicating guilt."
ACORN has been dogged by allegations of voter-registration fraud and embezzlement.
Several of its offices were the subject of an embarrassing hidden-camera sting in which ACORN employees were shown advising a couple posing as a prostitute and her pimp to lie about her profession and launder her earnings. The videos sparked a political uproar, with Republicans trying to use the group's troubles to portray Democrats as corrupt.
Adam Goldman of The Associated Press wrote this report.