Flow diverter stents are devices designed to treat complex aneurysms. According to preliminary series published in the literature, treatment of aneurysms with flow diverters is highly efficacious with acceptable morbidity and mortality. Delayed aneurysm ruptures have been reported but mechanisms are actually not completely elucidated. In-stent thrombosis or stenosis was also observed. Indications of flow diverters are complex aneurysms (fusiform, large and giant, wide neck, small aneurysms untreatable by conventional coiling) as well as recurrences. Several randomized studies and registries are actually in progress and will contribute to a more precise knowledge of the place of the flow diverters in the treatment of intracranial aneurysms.