Grassley pointed to evidence that a mass killer in Norway had played the popular "Call of Duty: Modern Warfare" game and had referred to the game as part of his "training simulation."
"Where is the artistic value in shooting innocent civilians?" Grassley asked.
President Obama and Vice President Biden have called for further studies to examine whether video games can lead people to commit acts of violence.
"I share Vice President Biden’s disbelief of manufacturer denials that these games have no effect on real-world violence," Grassley said.
Grassley's comments, which came in his opening statement, were some of the only mentions of violent video games during the hearing, which focused mostly on gun control proposals.
National Rifle Association CEO Wayne LaPierre has blamed violent video games for contributing to gun violence in the past, but did not mention the issue in his opening remarks.