Lay summary – Traumatic brain injury (TBI) affects millions of people worldwide each year and can lead to long-term disability, reduced quality of life, and increased risk of dementia. Despite this, TBI is often not properly recorded or treated as a long-term health condition by national health systems. This means governments may not have the information or resources needed to plan prevention, emergency care, rehabilitation, and long-term support for people living with the effects of TBI. This commentary explains why TBI should be officially recognised as both a notifiable condition, meaning it is routinely counted and monitored, and a chronic condition, meaning its long-term impact is acknowledged. It describes a growing international campaign involving health ministries, medical and rehabilitation specialists, researchers, the World Health Organization, non-governmental organisations, and people with lived experience of TBI. At a World Health Assembly side event in 2025, these groups showed strong support for better global recognition of TBI and for a future resolution that would help countries track, prevent, and treat it more effectively. Recognising TBI in this way would help ensure that survivors and families receive better care and support over time. It would also help governments build fairer and more effective health systems by making TBI visible in policy, funding, and public health planning.