The treatment of trigeminal neuralgia (TN), which is resistant to medical therapy, has benefited from many surgical techniques. It is not possible, in light of the present level of knowledge, to establish exactly which method is the most suitable. It does, however, seem significant that certain side effect appear, in varying percentages, in all kinds of operations. In 13 years, 2,094 patients suffering from TN have been treated by the authors with percutaneous Gasserian neurolysis, 128 patients with radiofrequency trigeminal neurolysis, and 1,966 with selective ethanolic trigeminal neurolysis (SETN). Our experience treating TN with controlled increments of ethanol by means of a needle introduced through the oval foramen in the Gasserian ganglion is related here. The tip of the needle is accurately placed among the roots desired under fluoroscopic control. The clinical effects on the conscious patient of a prognostic block with local anesthetics are evaluated before producing the neurolysis. Follow-up has been long enough to show that SETN is a highly selective procedure, which shouldn't be underrated in the centres that use it routinely