Wal-Mart said Friday that board Chairman Rob Walton will step down and be succeeded by Vice Chairman Greg Penner, who is Walton's son-in-law.
The company said the change will take effect at the end of its annual meeting Friday.
Walton, son of Wal-Mart founder Sam Walton, has been chairman since 1992. The company said the 70-year-old will continue to serve as a director.
Penner, 45, joined Wal-Mart as a management trainee and held a number of positions including senior vice president of finance and strategy. Rob Walton noted on stage at the meeting that Penner is married to his daughter.