Seth Rogen convinces Conan O'Brien to smoke marijuana on air

Seth Rogen managed to persuade U.S. TV host Conan O'Brien to smoke a joint on air during one of the final episodes of his talk show.

The late night host's show, Conan, will end its 11-year run on Thursday, so he threw caution to the wind and lit up on Tuesday night, when his guest Rogen, who's known for his stoner comedies, handed him a doobie.

The risque fun began with O'Brien asking the Pineapple Express star for ideas on ways to pass the time once he signs off as a late night host.

Seth, who owns his own cannabis company, suggested, "Try smoking a lot of weed for a long time."

The presenter then asked which kind of weed he should try, prompting the actor to pull out a pre-rolled joint from his shirt pocket and hand it over to the host.

"I think you should take one hit of that weed," said Seth. "And I think you'll have a really good time."

After O'Brien figured out how to properly hold the joint, he proceeded to light it and share it with both his guest and his TV sidekick, Andy Richter.

Riffing on the effect of the reefer, Conan asked, "When does this thing that's going to happen, happen?"

He then quipped, "I'm driving a school bus in an hour."

After the appearance, a bemused Rogen took to Twitter and told fans, "I smoked weed with @ConanOBrien his show and was legit terrified that I got him too high haha. (This was a surreal and shocking moment for me and was genuinely unplanned) (sic)".

Recreational cannabis is legal in California, where the show is taped.