Judicial notice is a court’s acceptance of a well-known and indisputable fact without requiring the party relying on the fact to prove it. The doctrine of judicial notice is one of common sense, and is based on the theory that where a fact is well-known in the community—or its existence is easily determined from sources that cannot be reasonably questioned—it would not be a good use of judicial time and resources to require formal proof of the fact in court. A court may take judicial notice of both facts and laws.

In Arizona, the concept of judicial notice is governed by the Arizona Rules of Evidence, specifically Rule 201. According to this rule, a court can take judicial notice of a fact that is not subject to reasonable dispute because it is either (1) generally known within the territorial jurisdiction of the trial court or (2) can be accurately and readily determined from sources whose accuracy cannot reasonably be questioned. This includes both adjudicative facts and law. Adjudicative facts are those facts that are not subject to reasonable dispute because they are generally known or easily verifiable. Arizona courts can also take judicial notice of the laws of the state of Arizona, federal laws, and the laws of other states. The court may take judicial notice at any stage of the proceeding, and it may do so on its own or upon request by a party. When a court takes judicial notice of a fact, it is accepted as true without the need for further evidence.