A blood blister-like (BBL) or dissecting aneurysm should be carefully considered if located at a non-branching site of the supra-clinoid internal carotid artery (ICA). Several surgical and endovascular treatment methods have been proposed but they all carry a relatively high risk of morbidity and mortality. This study evaluated the effectiveness of a novel Silk flow-diverting device (SFD) placed in the early acute stage. Three patients presenting with acute subarachnoid haemorrhage caused by small blister-like aneurysms of the carotid siphon were treated within 48 hours after admission by placement of SFDs. More than one device was placed to cover the lesion. None of the patients were premedicated and started anti-platelet therapy during the procedure. All aneurysms were successfully occluded. A good outcome was observed in two out of three treated patients. No thromboembolic or haemorrhagic event occurred during or after the procedures, or during follow-up (6-14 months). SFD prevented rebleeding and the use of these devices could be proposed as an option to treat fragile uncoilable BBL aneurysms, even in the early acute phase without anti-platelet premedication. Larger studies and long-terms results are necessary.