Brain tumours are challenging to treat, partly because the blood-brain barrier (BBB) hinders targeted drug treatment. Patients diagnosed with aggressive brain tumours like glioblastoma multiforme (GBM) present low median survival of 15 months despite surgery with concurrent chemotherapy and radiotherapy. The poor prognosis and limited therapeutic effect have led to the exploration for an alternative intervention: nanotechnology. This paper focuses on nanotechnology-based diagnostic tools and drug delivery systems, such as multifunctioning nanoparticles that comprise an anti-cancer drug, an imaging agent and tumour specific ligands, which enhances diagnostic sensitivity and therapeutic efficacy against the malignant cells.