In February, Franco served as co-host of this year's Oscars with Anne Hathaway.
At the taping for Friday's edition of "Late Show with David Letterman," Franco asked Letterman what his experience as Oscar host was like in 1995.
"It was horrible," Letterman replied. "I was so bad that they talked for a while about shutting down the motion-picture industry."
"But they didn't say you were stoned," Franco said.
"Oh, I quit reading, maybe they -- I wish I was," Letterman joked.
"I wish I was," Franco said. "People said I was under the influence."
Franco said he thought about why people might have thought that about him and he decided it was his co-host's fault.
"I love her, but Anne Hathaway is so energetic, I think the Tasmanian Devil would look stoned standing next to Anne Hathaway. ... She has a lot of energy," Franco said.
"I think I actually -- I haven't watched it back -- maybe I had low energy. I honestly played those lines as well as I could."