A 50-year-old woman developed a sudden onset of ophthalmoplegia. CT and MRI showed a massive middle cranial fossa tumour encasing the intracavernous sinus carotid artery. The tumour extended into Meckel's cave and sella, and had eroded the lateral wall of the orbit. Angiography showed a faint tumour blush and an aneurysm of the distal part of cavernous segment of internal carotid artery. On exploration, an extremely vascular, entirely intracavernous sinus cavernous haemangioma was completely excised and the aneurysm was clipped. The literature on this relatively rare and surgically formidable condition is reviewed.