"Gilmore Girls," starring Lauren Graham and Alexis Bledel and created by Amy Sherman-Palladino , "helped define a network and created a fantastic storybook world featuring some of television's most memorable, lovable characters," CW and the studio said in a joint statement.
They thanked fans for their "passionate support" and promised to give the show "the send-off it deserves."
Ratings had dipped this season for the series, which lost Sherman-Palladino as its guiding hand because of a contract dispute.
The drama with comic overtones followed single mom Lorelai Gilmore (Graham) and her equally bright and beautiful daughter as they grew up together, struggled through romances , and tried to find their place in the world.
Rapid-fire patter, the series' hallmark, delighted fans but took a toll on its cast.
"Getting the language perfect requires a number of takes that you might not have on another show," Graham said in an interview in January 2006. "It's just a lot of work -- 13, 14 hours door to door. I've missed weddings, I've missed babies being born. I'm not complaining, because of what it has brought me, but I would be ready for a different balance."
Sherman-Palladino and her husband and fellow executive producer, Daniel Palladino, left after failing to come to terms with the studio on a new deal, and the series struggled creatively and in the ratings this season. The April 24 episode drew fewer than 4 million viewers, down about 25 percent from the same time last year.
As production on the show got under way last fall, its future then uncertain, Graham speculated about the final chapter.
"I care very much how the story ends," Graham said. "It would be my worst nightmare if we end the show with a wedding. To me, the premise of the show was, 'What if your parent was your best friend?'
"That's the thing you leave people with, the strength of this family and this relationship," she said.
Locking in "Gilmore Girls," one of the CW's few unqualified successes, had been a priority for the new network. As the TV networks get ready to announce their new shows to advertisers later this month, the CW has few sure things on its schedule. "Veronica Mars," its comedies, and "Supernatural" all have struggled in the network's first year.
Material from the Los Angeles Times was used in this report.