Haynesworth played college football in the University of Tennessee. He has a history of issues with his temper. For example, while a sophomore at Tennessee, he fought with a teammate and left practice, returning with a long pole looking for tackle Will Ofenheusle before coach Phillip Fulmer stopped him. He was suspended for a half of a game. Another incident occurred at a Titans training camp, where he kicked center and teammate Justin Hartwig in the chest, and had to be restrained by teammates.

Arrest warrants were issued against Haynesworth in two Tennessee counties in May of 2006 stemming from a traffic incident on Interstate 40. Both sets of charges were dropped in June of 2006. The Judge in the Putnam county case tossed the charges on the grounds that the alleged offense happened out of their jurisdiction. In Smith county, the district attorney dismissed the charges.

On October 1, 2006, in the third quarter of a game against the Cowboys, running back Julius Jones scored on a running play. Center Andre Gurode fell to the ground, and his helmet fell off. Haynesworth tried to stomp on Gurode's head, but missed. A second stomp opened a severe wound on Gurode's forehead, narrowly missing his right eye. Haynesworth was hit with a 15-yard penalty for unnecessary roughness. In the midst of his protest, he took off his helmet and threw it to the ground, which led to another 15-yard penalty and Haynesworth's ejection from the game. Gurode later received 30 stitches just above and below his right eye. After the game, Titans coach Jeff Fisher apologized on behalf of the Titans organization to Cowboys coach Bill Parcells