Protoplasmic astrocytoma is an extremely rare form of grade II low grade glioma which usually presents as a discrete mass lesion. We describe a 3-year-old female with diffuse protoplasmic astrocytoma with parenchymal involvement and leptomeningeal spread. This tumour proved extremely difficult to diagnose and followed a progressive course. Three superficial biopsies did not give the diagnosis and this was only confirmed 8 months from presentation from a larger fourth biopsy taken deeper from the cerebellum. To our knowledge this case represents the distinct presentation of protoplasmic astrocytoma presenting as extensive diffuse meningeal disease.