It is the first time World Cup organizers in Qatar have announced a work-related death in regard to the tournament, AFP reported.
"It is with deep regret we announce a work-related fatality on one of our projects" following "an incident on Al-Wakrah Stadium on Saturday morning," said the Supreme Committee for Delivery and Legacy.
"A full investigation is underway to determine the factors which contributed to the death of one of our workers," it added.
The statement did not identify the worker or give details on the nature of the incident.
Qatar has been widely condemned for its treatment of foreign workers.
The issue of deaths among migrant laborers helping build stadiums for its $30 billion tournament has long proved controversial.
Critics have claimed that 1,200 workers have already died and up to 4,000 could perish before the World Cup begins, a figure vehemently denied by Qatar.
Qatar has an estimated 1.6 million migrant workers, more than 85 percent of the entire workforce, according to government figures released at the end of 2015.
The number of workers employed on World Cup sites in Qatar is expected to peak at 36,000 by 2018.
In February, organizers said six laborers building stadiums for the tournament suffered work-related injuries last year but there were no fatalities.
In May, it was announced an investigation had been launched into the death of an Indian worker at the Al-Bayt stadium, but organizers denied his death was work-related.
Shaped to look like a traditional dhow boat, Al-Wakrah stadium has a capacity of 40,000 and will be used up to the quarterfinal stages in 2022.