3D time-of-flight magnetic resonance angiography (3D TOF MRA) and 2D MRA with presaturation were evaluated in 18 patients with 21 giant intracranial aneurysms. 3D TOF MRA gave optimal images of proximal unruptured and nonthrombosed aneurysms. 2D MRA with presaturation was more informative in cases of distal, haemorrhagic or thrombosed aneurysms and in assessment of their components (thrombus, haemorrhage, patent residual lumen).