Prima facie is a Latin expression (come by way of Middle English) meaning “on its first appearance,” or “by first instance” used in common law jurisdictions to denote evidence that is sufficient, if not rebutted, to prove a particular proposition or fact. In most legal proceedings, one of the parties has the burden of proof, which requires that party to present prima facie evidence of all facts essential to its case. If that party fails to present prima facie evidence on any required element of its case, its claim may be dismissed without any response by the opposing party. A prima facie case may be insufficient to enable a party to prevail, however, if the opposing party subsequently introduces contradictory evidence or asserts an affirmative defense. Sometimes the introduction of prima facie evidence is informally called making a case or building a case.

For example, in a criminal prosecution, the Government has the burden of presenting prima facie evidence of each element of the crime charged. In a murder case, this would include evidence that the defendant’s act caused the victim’s death, and evidence that the defendant acted with malice aforethought. If the prosecution were to fail to introduce such evidence, then its case would fail on grounds of “failure to make out a prima facie case,” even without rebuttal by the defendant. This evidence need not be conclusive or irrefutable, and evidence rebutting the case may not be considered.

Prima facie is often confused with res ipsa loquitur (“the thing speaks for itself”), the common law legal doctrine which in its modern incarnation allows a tort plaintiff to reach the jury on the question of a defendant’s negligence, despite the plaintiff’s failure to produce any evidence explaining exactly how the defendant was negligent, by establishing circumstantial evidence from which unspecified negligence by the defendant can fairly be inferred.

The phrase prima facie is sometimes misspelled *prima facia in the mistaken belief that *facia is the actual Latin word; however, the word is in fact faci?§s (fifth declension), of which faci?§ is the ablative.

The phrase is very commonly used, in exactly the same sense, in academic philosophy as well. Among the most notable uses of it in that discipline is the theory of ethics first proposed by W. D. Ross, often called the Ethic of Prima Facie Duties.