According to ABC News, the suicidal woman was on the edge of a balcony and threatened to jump when the three men heard the commotion and rushed into the building to rescue her.
Amos Carver, Gregg Sergeant and Scot Schecter were on the other side of the road setting up for a Kick-Ass 2 private party in the San Diego district hosting Comic-Con. Sprinting across three lanes of traffic and scaling a fence, the men ran into the room before managing to pull her back over the balcony.
Carver told ABC: "We went through the apartment trying to be as quiet as possible. We didn't want to alert her that we were there."
They found the woman, who they believe to have been heavily intoxicated, hanging on with one hand, and with one foot off the ledge.
"She just kept saying 'I'm so sorry, I'm so sorry' over and over again. She was very distraught."
The suicide attempt was first mistaken for a promotional stunt by onlookers accustomed to movie studios going all out at the annual event.
The identity of the woman has yet to be released, but it is thought that she was upset over a breakup.
"We're trained to deal with these situations should they arise," said Carver, who compared the rescue with working on a film set. "But usually if we do, it's not an innocent civilian."