Charles Wilson, Tesco's UK chief executive, is stepping down from his post on the company board after being diagnosed with throat cancer.
Mr Wilson was formerly boss of food wholesaler Booker, but became Tesco's UK chief following the supermarket's £3.7bn takeover of Booker in March.
Tesco said Mr Wilson had responded well to treatment and all the signs were that it had been successful.
"Following an operation to remove his tonsils in April of this year, Charles Wilson was diagnosed with throat cancer," Tesco said in a statement.
"During May and June, he has been undergoing daily radiotherapy."
