World War Z filmmakers will be in George Square, which has been transformed into Philadelphia, to shoot the latest dramatic scenes.
Around 400 extras and 300 crew members will be filmed fleeing from zombies – and movie fans will be in the city hoping for a glimpse of Pitt.
Yesterday, even though they are filming in one of Scotland's wettest cities, the production team was forced to fake rain as the cameras continued to roll.
Hundreds of extras gathered on the streets and then ran through a mass panic scene in which they appeared to flee from the zombie apocalypse.
A crash between an ambulance and a Volvo was also being set up.
Meanwhile Brad Pitt spent his day off from filming zombie flick World War Z by indulging in his love of Mackintosh architecture.
The heart-throb visited Hill House in Helensburgh along with partner Angelina Jolie.
Staff at the historic tourist attraction said a private tour had been booked for 10 people but instead of the expected tourist party, the two Hollywood A-listers – along with their entourage – turned up.
They also revealed the couple, who have been staying at Carnell Estate in Ayrshire. splashed out in the gift shop, enjoyed a cup of tea and wrote their names in the guest book.
Retail manager Karen Fenwick, said the visit was "fantastic".
She said: "They were here for about two hours, and the manager gave them a tour.
"They spent some money in the gift shop on Mackintosh things and some novelty pencils for the children."
It was Brad's second visit to Hill House – which was built for Glasgow publisher Walter Blackie between 1902 and 1904 and is held as one of Mackintosh's finest works.
The 47-year-old star went there when he was filming Interview With a Vampire in 1994. He also visited another Mackintosh masterpiece at that time, the Glasgow School of Art.
Lorna Hepburn, the National Trust for Scotland's manager at Hill House, said the pair were "relaxed and friendly and clearly interested and knowledgeable".
She added: "We treated them with the same courtesy we would extend to any visitor and let them enjoy their tour without intrusion or interruption."
Lorna admitted after the Hollywood stars were gone the team all felt "exhausted but grateful to realise Hill House is so renowned and appreciated from Helensburgh to Hollywood."
Angelina, 36, also took advantage of her time in Scotland by visiting the Halo Trust centre, the global headquarters of a landmine charity she supports.
The star arrived at the centre in Thornhill, Dumfries, on Saturday afternoon and stayed for around two hours.