University of Texas Southwestern Medical Center v. Nassar, 570 U.S. 338 (2013), was a Supreme Court of the United States case involving the standard of proof required for a retaliation claim under Title VII of the Civil Rights Act of 1964.

[1] The Court held that while Title VII applies a mixed motive discrimination framework to claims of discrimination on the basis of race, color, religion, sex, or national origin (see 42 U.S.C.

The Court reasoned that based on its decision in Gross v. FBL Financial Services, Inc. and on common law principles of tort law, the plaintiff was required to show that a retaliatory motive was the "but for" cause of the adverse employment action.

Prior to his resignation, Dr. Nassar had requested and received an offer to continue working at Parkland Hospital, but after receiving his resignation letter, the university instructed the hospital to withdraw the offer.

The Court determined that Title VII's mixed motive discrimination did not apply to retaliation claims, and therefore Gross v. FBL Financial Services, Inc. was instructive.