National Treasury Employees Union v. Von Raab, 489 U.S. 656 (1989), was a United States Supreme Court case involving the Fourth Amendment and its implication on drug testing programs.

The majority of the Court upheld the drug testing program in the United States Customs Service.

In 1986, the U.S. Customs Service imposed a drug testing program for "employees seeking transfer or promotion to positions having direct involvement in drug interdiction," required to carry firearms, or have access to classified information.

The National Treasury Employees Union sued and alleged that the program was violative of the Fourth Amendment, which prohibits unreasonable search and seizure.

The majority decision authored by Justice Kennedy upheld the constitutionality of the drug testing program, reasoning that Customs employees had a "diminished expectation of privacy."