The authors' experience in the routine use of temporary clipping procedures in the surgery of endocranial aneurysms is reported. To analyse the validity of such a method we compared the outcome in a series of 153 aneurysms operated according to the traditional procedure (temporary clipping of the afferent vessel only in the case of intraoperative rupture of the aneurysmatic sac) with that of a more recent series of 225 in which the procedure was applied routinely. An unsatisfactory surgical outcome was found in 12.5% and 6.6% of patients respectively, with a corresponding unfavourable outcome in 5.6% and 2.6%.