The most common plant constituents of Ayahuasca (Banisteriopsis caapi & Psychotria viridis) are not specifically scheduled in the United States. Neither is the ayahuasca brew specifically named as a scheduled substance. However, P. Viridis contains DMT which is DEA schedule 1. The DEA has recently been making the argument that a plant or brew is illegal if it contains DMT or any other controlled substance.

Major court decisions in the United States in 2006 and 2009 have left the religious use of ayahuasca more or less legal for the protected groups, the UDV and Santo Daime (see UDV Wins Supreme Court Case and Santo Daime Wins Court Decision). It is likely that the Drug Enforcement Administration will continue to fight to get those rulings overridden. As of March 18, 2009, it is still presumptively illegal in the United States to use ayahuasca unless one is a member of the two churches that have successfully sued the U.S. government.

• Mar 2009: Oregon Court Rules Santo Daime is allowed to import their DMT-containing brew
• Apr 2005: U.S. Supreme Court Agrees to Hear Government Appeal of Preliminary Injunction
• Dec 2004: Supreme Court Allows UDV to use Tea by Lifting Temporary Stay of Preliminary Injunction
• Nov 2004: Appeals Court Affirms Previous Appeals Court Affirmation
• Aug 2003: Appeals Court Affirms Lower Court Preliminary Injunction
• August 2002: UDV Wins Preliminary Injunction in Ayahuasca Case
• November 2001: UDV Ayahuasca Legal Case Begins in New Mexico
• 2000, 2001: Ayahuasca tea seized by DEA in Oregon and New Mexico
• January 2000: Plants used to make ayahuasca seized by the DEA and importer arrested in Georgia