Thomas Gunderson was attending the Route 91 Harvest Festival on Sunday night when he was horrifically injured when Stephen Paddock, 64, sprayed bullets on more than 20,000 concertgoers.
Gunderson, of California, said he was running toward Mandalay Bay when a bullet pierced his leg.
President Trump and First Lady Melania flew to Las Vegas where they visited several victims of the shooting on Wednesday.
But they were suprised when Gunderson stood up to greet both of them despite his leg injury, and a family member captured the entire moment on video.
Gunderson is seen trying to sit up in the hospital bed as the first lady walked in.