The 200-kilogram British bomb was found on November 2 by workers extending a local cinema.
Believed to have been dropped in 1941, the bomb had been damaged by equipment at the building site, making the operation more complex.
But army specialists managed to defuse the device and were expected to detonate it at a remote site on Monday.
More than half of the Apulian city’s population was evacuated at 8:00 am, and gas supplies in homes within 500 metres of the site were cut.
Brindisi’s airport, train station, two hospitals and a prison were all evacuated.
More than 200 inmates were moved to the prison in Lecce, 38 kilometres away.
Some air traffic and rail services were also suspended.
More than a thousand members of the security forces and around 250 volunteers took part in the evacuation operation.
Unexploded ordnances are still a problem throughout Italy, especially near the border with Austria, where most of the undiscovered ones are believed to be.
According to statistics from the Italian defence ministry, thousands of World War II bombs are defused in the country every year.
