The incident happened four months after he nearly lost a finger.
This time, Fallon reportedly tripped and fell while holding a bottle of Jägermeister. A source said to People, "It was all part of the celebration in the street, and some random girl kneeled down in front of him abruptly as he was turning around and he tripped over her because he didn't see her."
Another parade-goer shared, "Jimmy went to the ground, and everybody asked if he was okay. He said he was fine."
Watch what happened to Jimmy in the Instagram video below, which was captured by a fan, who wrote, "Jimmy Fallin folks! #jimmyfallon #latenightwithjimmyfallon #harvard @jonthesneider and @johndoomsdayhoward."
After the accident, Fallon headed straight to Massachusetts General Hospital to be treated for his injury. On Sunday, he posted a photo of his right hand and wrote on Instagram, "Nothing that a few band aids couldn't fix."