The man was struck on the head by a falling metal bar from a crane in which he was helping to dismantle. He was rushed to hospital, where he received neurological treatment, however local authorities confirmed that he died a few hours later, early on Friday afternoon.
He was identified by the Brazilian Sports Ministry as 55-year-old Antonio Jose Pita Martins.
Martins had been working for a multinational construction company Martifer, which outsources personnel to the site's main contractor, construction company Andrade Gutierrez.
Martifer representatives told Brazil's Globo News that it would provide all necessary assistance to the victim's family.
The city's World Cup secretary, Miguel Capobiango, said the crane was being dismantled as work at the site was almost complete.
A government inspection of the site, planned for Friday, was cancelled. It had been expected that Governor Omar Aziz would announce when the stadium was going to be inaugurated.
Martins was the fourth person to have been killed in Manus in connection with the World Cup stadium's construction.
Two workers fell to their deaths in 2013 in separate incidents in March and December 2013. Another worker suffered a fatal heart attack: his family later said he had been overworked.
Following the most recent fatal incident, in December, a court suspended work on the stadium and a follow up investigation found that the working conditions on the site were “dangerously unacceptable”.
Two workers were also killed in late November at the Arena Corinthians in São Paulo, when a crane maneuvering a section of the roof collapsed. The stadium in Brazil is due to host the World Cup's opening game on 12 June.
In addition, another worker died at the construction site of the World Cup Mané Garrincha stadium in the country's capital, Brasília, in 2012.