In May 2010, Kassian was charged with assault after an altercation outside of a downtown Windsor, Ontario bar. In October 2010, Kassian reached an agreement that saw the assault charge laid against him in May dropped. As part of the deal, Kassian, 19, must perform 25 hours of community service. He will also make a $500 donation to charity and pay for the dental work of the other person involved in the incident. Kassian was arrested shortly after the completion of the Memorial Cup after an altercation at a Windsor bar. If convicted of the charge, Kassian could have run into difficulty crossing the Canada-U.S. border as he looks to continue his hockey career.
On April 23, 2011, Kassian was suspended 4 games for an intent to injure match penalty he received at the end of a playoff game vs the Owen Sound Attack on April 23, 2011.