The need of an emergency bypass in hazardous situations during treatment of intracranial aneurysms has rarely been addressed in the literature. We report our 10 year experience with emergency bypass for aneurysm treatment. We retrospectively analyzed the data of patients who underwent emergency bypass surgery for the treatment of an intracranial aneurysm and compared the results with patients treated with bypass as a planned procedure during the same time period. Three groups were formed: group I, emergency bypass during clipping procedure; group II, emergency bypass for therapy refractory vasospasm; group III, planned bypass surgery. Sixteen patients (35%) out of 46 were treated with emergency bypass. In group I (11 patients) mortality was 37% and a good outcome (GOS 4 & 5) was achieved in 36%. In group II (5 patients) mortality was 20% and good outcome was reached in 60%. In group III (30 patients) mortality was 10% and good outcome was achieved in 86.6%. Outcome was worse in patients with additional SAH. An emergency bypass procedure as part of the aneurysm treatment should be considered in risky situations. Accurate timely decision-making is crucial combined with a fast and secure bypass technique. Treatment of refractory vasospasm with emergency bypasses may help to improve outcome in selected patients.