Stib placed an initial order for 46 vehicles in October 2003 and the authority exercised an option for 22 vehicles in September 2005, followed by a second option for 87 units in January 2008. In 2010 Stib placed a second order for 87 vehicles.

The Brussels Flexity fleet comprises 150 31.85m-long five-section T3000 vehicles, which accommodate up to 180 passengers, and 70 43.22m-long seven-section T4000s which have capacity for up to 252 passengers.

Stib is currently developing a specification for its next order for low-floor LRVs, which will enter service from 2018, replacing ageing PCC trams and providing additional fleet capacity for the expansion of the network.