Subependymomas (SE’s) are infrequent benign glial neoplasms closely related to the ventricular system. Rarely do they present with symptoms or acute haemorrhage. This case reports a 76-year-old male presenting with severe headache and decreased consciousness in the setting of a known septum pellucidum (SP) lesion and a synchronous meningiothelial meningioma. CT revealed a right lateral intraventricular haemorrhage extending to the third and fourth ventricles with associated acute hydrocephalus. CTA established the SP lesion as the source of the acute bleed. Emergency external ventricular drainage was performed followed by stereotactic fronto-parietal craniotomy and sub-total resection. Histology was notable for a WHO Grade I subependymoma. Our patient represents only the third reported case with haemorrhage into an SP subependymoma, and the first reported case of a co-existent meningiothelial meningioma. The pertinent diagnostic and management aspects of this rare lesion in an extraordinary location with an uncommon complication are herein discussed.