We report the long term results of the treatment of 23 intracranial ruptured aneurysms by coating. Twenty-three patients treated by coating were followed for a mean period of 11.2 years. The mean interval between the last hemorrhage and the operation was 22.4 days. Ten aneurysms underwent total coating, 9 with Biobond and 1 with Aron Alpha. Thirteen aneurysms underwent partial coating, 11 with Biobond and 2 with Aron Alpha. Six aneurysms were reinforced partially by other materials, but no aneurysm was wrapped totally with these materials. Rebleeding occurred in 6 patients, of whom 5 died. The mean interval between coating and rebleeding was 4 years. All patients suffering rebleeding had been treated with Biobond, and 3 patients had undergone total coating of aneurysms. The risk of recurrent hemorrhage after total coating with Biobond was 33%. One rebleeding patient underwent a second operation 10.5 years after total coating of the aneurysm. Biobond was found only at the tip of the aneurysmal sac. From these results, reinforcement of ruptured aneurysms with Biobond seems to be of little value, and a more reliable method must be developed for aneurysms that cannot be clipped. (Neurosurgery 21:660-663, 1987)