Gerhart rushed for over 100 yards in 11 of his 13 games in 2009. On September 26, 2009, he became only the sixth person in Stanford history to rush for 200 yards in a game, with 200 yards on 27 carries against Washington. On November 7, 2009, Gerhart recorded his second 200-yard game of the season, running for 223 yards against the 7th-ranked Oregon Ducks, breaking the Stanford single-game rushing record previously held by Jon Volpe. On November 28, Gerhart ran for 205 yards and three rushing touchdowns in a 45-38 win over Notre Dame. This was his third 200-yard game of the season. Gerhart again tied the school record for rushing touchdowns in a game by running for four touchdowns against Cal. Gerhart also threw one pass in 2009, completing it for an 18-yard touchdown against Notre Dame.