CBS chief executive Leslie Moonves said Tuesday that Letterman has carried his jokes about Moonves' recent trip to Cuba "a little longer than I'd like."
"Some of it is funny and some of it isn't," said Moonves, a frequent target of the Late Show host's barbs.
Some industry trade publications recently reported that Moonves joined a group of other entertainment executives on a jaunt to Cuba, where they met with communist leader Fidel Castro.
Letterman quickly picked up on the story. Along with mocking Moonves, he frequently poked fun at General Electric executives when he worked at NBC, which is owned by that corporation.
On Monday's show, Letterman had a skit, "Lunch with Les and Fidel." A character portraying Castro said, "Les, throughout the decades, to insure a strong dictatorship, I have starved my countrymen and tortured and murdered my political opponents."
The Moonves character answers: "The Bette Midler show was my idea."
Moonves, in a conference call with reporters on Tuesday, said his negative review comes more because he doesn't think many viewers know who he is or care about his trip to Cuba.
"I'm more concerned about whether it is funny or not than whether it is about me," Moonves said.
But Moonves said that "Dave is Dave." And he said he didn't mind that Letterman was also taking frequent potshots at Survivor II, the network's most popular prime-time program.
A spokeswoman from Letterman's show had no comment about Moonves' remarks.