The Glasgow Coma Scale (GCS) was first published in The Lancet by Sir Graham Teasdale and Bryan Jennett 50 years ago based on their pioneering work on developing a numerical scale to describe coma in clear and reproducible terms and to avoid the confusion associated with the wide variety of descriptive terms for consciousness that were in use at the time. It's difficult to know if Teasdale and Jennett could have predicted how influential, widespread and long-lasting the GCS would become, but in retrospect it seems clear that the GCS was introduced at a perfect stage in the development of modern clinical neurosurgery and neuroscience research. The simplicity of the scale, its recognition by senior academics and the emerging radiology technologies in the 1970s heralded a new era of neuroscience and an approach to the management of not only traumatic brain injury (TBI) but other types of central nervous system disease in which consciousness was affected, such as aneurysmal subarachnoid haemorrhage and stroke. Together with its sister scale the Glasgow Outcome Scale, the GCS remains extremely relevant in clinical neurosurgery and neuroscience research, and despite the proposal of various alternative scales the GCS endures in the modern management of TBI.