Extraordinary rendition has had a general meaning, in U.S. law, of obtaining custody of a prisoner, from a foreign country, without a formal extradition procedure . The traditional meaning had been to bypass extradition by requesting a country to deport or expel a non-citizen, into the custody of U.S. personnel.  It is a practice of the United States government, where captives are transferred from US custody without going through the regular channels of international extradition, although the process may or may not involve a hearing in the country involved.
Captives who face extraordinary rendition may or may not have an opportunity to challenge the justification for their transfer. Such captives would typically make their challenge to the immigration authorities in that country, if they are not citizens of it, rather than to its courts.
Legal distinctions have been drawn between secret rendition when there is, or is not, the possibility of torture. Using the doctrine of state secrets, the U.S. Court of Appeals for the Fourth Circuit in a unanimous decision, dismissed the action of Khaled el-Masri  asserting claims related to his extraordinary rendition. One of the concerns in this case, involving a German citizen, was the Council of Europe of June 2006 had reported that el-Masri's account of having been abducted and mistreated was substantially accurate. 
Human rights critics have expressed the concern that the United States initiates secret extraordinary rendition, and requests nations where the use of torture is routine to subject selected important captives to interrogation techniques prohibited by US law.  .
The policy of the Obama Administration has not been fully elaborated, although this Administration has taken a strong policy against torture. Former United States President George W. Bush has asserted that the US Government does not send captives to countries where they will be tortured
However, I can tell you two things: one, that we abide by the law of the United States; we do not torture. And two, we will try to do everything we can to protect us within the law. We're facing an enemy that would like to hit America again, and the American people expect us to, within our laws, do everything we can to protect them. And that's exactly what the United States is doing. We do not render to countries that torture. That has been our policy, and that policy will remain the same.
- , USAM Chapter 9-15.000, International Extradition and Related Matters, US Attorneys' Criminal Resource Manual, U.S. Department of Justice
- El-Masri v. Tenet, (United States District Court for the Eastern Division of Virginia, Alexandria Division December 6, 2005)
- Benjamin G. Davis. The Un-American Way: The Kafkaesque Case of Khalid El-Masri, The Jurist, March 5, 2007. Retrieved on 2008-04-15.
- Greg Sampson. Bush denies US rendition for torture but Rice acknowledges 'mistakes', The Jurist, Tuesday, December 6, 2005. Retrieved on 2008-04-15.
- Aziz Huq. Dangerous Discretion: State Secrets and the El-Masri Rendition Case, The Jurist, March 12, 2007. Retrieved on 2008-04-15.
- George W. Bush. President Meets with World Health Organization Director-General, White House, December 6 2005. Retrieved on 2008-04-15.