STIB has its own security service with more than 300 security agents to ensure the safety of customers, staff and public transport facilities in Brussels. These agents carry out intervention and inspection tasks on the network. More than 250 multimodal agents also perform passenger information, infrastructure verification and prevention tasks. The objective is to provide an enhanced human presence on the network and make customers' journeys more pleasant. Network security also involves a major surveillance camera system, with 6,000 cameras on board vehicles and 3,450 in stations.

In total, 25,374 missions (surveillance, security, ticket control, etc.) were carried out by the STIB security service in 2020, i.e. an average of about 70 missions per day.

As a result of the COVID-19 pandemic, the tasks of STIB's security staff were temporarily redirected towards monitoring customers' compliance with health measures (social distancing, mask-wearing, etc.), in collaboration with the police services.