The 'Drag Me To Hell' star, who is currently dating Hollywood actress Drew Barrymore, claimed a fan made the comparison when he was enjoying an evening out.
He told New York Daily News newspaper: "I was smoking at a club one night, and this girl walked up to me and said, 'I can't believe you're smoking after playing someone in a hospital all this time!
"I couldn't for the life of me figure out who she thought I was. Then she leaned over and said, 'I think your best work was in 'Garden State'."
Justin - who is currently voicing the part of Alvin in the 'Alvin and the Chipmunks: The Squeakquel' film - did not take the comparison well.
He replied: "Zach Braff? Really?"