Filip Saska and Tomas Nadrchal, both of the Czech Republic, and Stephen Michelman, of Manhattan, filed the lawsuit in Manhattan Supreme Court, the New York Daily News reported Wednesday.
The three alleged they were duped into paying admission to the museum, although it is free to the public.
"We have obtained evidence which makes clear to us that the museum is actively misleading the public and that members of museum's leadership are fully aware of that fact," said lawyer Michael Hiller.
The suit cites a large "Admissions" sign that lists prices of $25 for adults, $17 for seniors, and $12 for students, and only notes that these are recommended donations in small print at the bottom.
The suit comes just four months after a similar suit accused the museum "defrauding" the public for the same reasons.
Museum spokesman Harold Holzer ripped the suit as a "second attempt for publicity around the same baseless lawsuit that was filed a few months ago."