The cable channel has picked up Bill Maher's political chatshow for two more seasons, guaranteeing it will remain on the air at least through 2013.
HBO programming president Michael Lombardo said of the renewal: "Bill Maher's irreverent wit and fearless insights make him the perfect observer for these unpredictable times.
"I'm delighted that we can continue to offer an uncensored forum for his original and thoughtful humour."
Real Time debuted on HBO in February 2003, several months after his previous series Politically Incorrect had been cancelled.
Sean Penn, Michael Moore, former New York Governor Eliot Spitzer, Martin Bashir and Jon Hamm are among the notable guests who have appeared throughout Real Time's nine-year history.
Real Time with Bill Maher airs Fridays at 10/9c on HBO.
Maher also recently made headlines when he donated $1m (£619,732) to US President Barack Obama's re-election campaign.
> Bill Maher defends Rush Limbaugh apology to Georgetown student
Watch one of Bill Maher's 'New Rules' below (mature content):