An estimated 65.6 million people watched President Barack Obama and Mitt Romney face off in their contentious second presidential debate.
The Nielsen company said that was down slightly from the 67 million viewers for the candidates' first debate a week ago.
But it was still a bigger audience than any of Mr Obama's debates with John McCain four years ago, and the biggest audience for a second debate since 1992.
The town-hall style debate from Hofstra University on Long Island was televised live by 10 networks and on tape delay by the Spanish-speaking Univision and Telemundo.
Fox News Channel narrowly missed setting a record for the network's biggest audience ever.