Most surgical procedures proposed for treating the "tic douloureux" present some untoward side-effects. Very often retrogasserian neurotomy leaves behind troublesome losses of sensitivity with disabling sequels as corneal ulcers. Tractotomies are less dangerous, as far as sensitivity is concerned, but unfortunately they require more difficult technical procedures. Decompressive operations upon the "cavum Meckeli" have a very high recurrence rate. The recent experimental investigations performed by King et al. and by Crue and Sutin reinforce the concept that, in order to reduce the paroxystic cranio-facial pains, it is sufficient to relieve a hypothetic internuncial pool, by suppressing important peripheral sensitive impulses. Retrogasserian rhizotomy is the best operation, according to our judgement, but the neural section must always include nothing more than the caudal 2/3 neurofibrils : with this technique our 26 patients obtained improvement, even those painful complaints referred to areas with no correspondence to the projection of the nerves divided.