Current knowledge on the biology and clinical features of brain tumours is reviewed with particular reference to the most commonly occurring tumours - gliomas, meningiomas and metastases. Unfortunately, the enormous increase in understanding of the biology of these tumours over recent years has not, as yet, been paralleled by advances in treatment or improvements in clinical outcome. Developing adjuvant therapies, ranging from novel means of delivery of radiotherapy and new chemotherapy agents to gene therapy and anti-angiogenic agents, are currently being explored and offer some hope for improvement in our ability to treat these tumours over the next few decades.