United States v. Montoya De Hernandez, 473 U.S. 531 (1985), was a U.S. Supreme Court case regarding the Fourth Amendment's border search exception and balloon swallowing.

[1] Rose Elvira Montoya de Hernandez entered the United States at Los Angeles International Airport from Bogotá, Colombia.

Customs inspectors detained Montoya de Hernandez upon her arrival based upon a suspicion that she was smuggling drugs.

The defendant had claimed that she was pregnant, and she was given the opportunity to undergo an X-ray, but she refused after being informed that she would have to be handcuffed en route to the hospital.

She had a noticeable bulge in her abdomen when she was detained, and a female inspector searched her revealing that Montoya de Hernandez was wearing two sets of elastic underpants and had paper towels lining her crotch area (as balloon swallowing makes bowel movements hard to control).