Hearsay is a statement that (1) the person making it (the declarant) does not make while testifying at the current trial or hearing (in other words, the statement is made out of court); and (2) a party offers as evidence to prove the truth of the matter asserted in the statement.

Hearsay is generally not admissible as evidence—but there are many exceptions to hearsay, and statements that are non-hearsay. The law governing hearsay is usually located in the applicable state or federal rules of evidence, which are interpreted and applied by courts in court opinions or cases.

In New Mexico, hearsay is addressed under the New Mexico Rules of Evidence, which largely mirror the Federal Rules of Evidence. Hearsay is defined as an out-of-court statement made by a declarant that is presented in court to prove the truth of the matter asserted in the statement. Generally, hearsay is not admissible in court because it is considered unreliable due to the lack of opportunity to cross-examine the declarant. However, there are numerous exceptions to this rule. For instance, statements made under the belief of impending death, certain statements against interest, and statements made in the course of a regularly conducted activity are among the exceptions that may allow hearsay to be admitted as evidence. Additionally, some statements are defined as non-hearsay because they are not offered to prove the truth of the matter asserted, such as a statement offered to show the effect on the listener or to prove the speaker's state of mind. The specific application of hearsay rules can be complex and is often determined by the context in which a statement is made and the purpose for which it is offered in court.