Betty Dukes, a Walmart worker who led a class-action lawsuit accusing the company of discriminating against female employees — a landmark case that went all the way to United States Supreme Court — died on July 10 at her home in Antioch, Calif. She was 67.

Her death was confirmed on Tuesday by her brother William Ponnell. The cause had not been determined, but she had recently had heart problems, he said. Ms. Dukes had continued to work for Walmart until her retirement last year, a company spokesman said.

A Walmart greeter who welcomed customers to the store, Ms. Dukes was portrayed as the epitome of a low-paid female retail worker taking on a huge multinational corporation.

“She was a voice fighting for equal rights and against racial and gender discrimination in the workplace,” her niece Rita Roland said.