He was being treated at Cedars-Sinai Medical Center for cancer discovered during a routine examination a few weeks ago, said Marcia Newberger, spokeswoman for The Griffin Group/Merv Griffin Entertainment.
"I'd rather play Jeopardy! than live it," the 82-year-old game show impresario and former talk show host said in a statement. "I was ready for a vacation; however, this wasn't the destination I had in mind."
Griffin's son, Tony, said his father was resting comfortably and that "his sense of humor and optimistic outlook remain intact."
"He's getting great care and his medical team want to monitor his progress in a controlled setting," Tony Griffin said in a statement.
Newberger declined to give additional details.
Griffin, a former band singer, invented and produced the popular game shows "Jeopardy!" and "Wheel of Fortune."