While intraventricular haemorrhage is frequently found in association with intraparenchymal or subarachnoid haemorrhage, isolated intraventricular haemorrhage (iIVH) is rare in adults and seldom described. Awareness of possible causes is important in order to guide patient management. After elimination of a traumatic cause, numerous aetiologies remain possible. The most frequently found underlying lesions are arteriovenous malformations and aneurysms, but other vascular causes should also be sought, including cavernous malformations and moyamoya disease. Arterial hypertension, anticoagulant use, coagulopathies and certain toxic substances are also associated with iIVH. Finally, iIVH may be caused by intraventricular tumours. In a high number of cases, the cause remains unknown. Vascular and non-vascular causes should be searched through an imaging work-up (with CT angiography, MRI and catheter angiography when necessary) and correlation with clinical information to yield a diagnosis. The aim of this pictorial essay was to review the aetiologies of iIVH in adults.