An adversary proceeding is a lawsuit that is brought in Bankruptcy Court. Litigation in Bankruptcy Court is similar to other litigation, but generally it has tighter timelines and deadlines than litigation in other courts.

Adversary proceedings can be brought by the Debtor (the party that filed bankruptcy), a creditor, a Bankruptcy Trustee, or the United States Trustee. The United States Trustee is part of the United States Justice Department.