Fifty patients complaining of trigeminal neuralgia have been treated by Percutaneous Retrogasserian Glycerol Rhizotomy (PRGR) from September 1983 to December 1985. In 94% of cases the procedure was successful in relieving pain with minor facial sensory loss, in 29 cases confined to the affected divisions, in 13 cases extending in an adjacent division. A herpes eruption occurred in 39 patients. A partial relapse (not requiring re-operation) verified in 12 patients. Even it firm conclusions cannot be reached as to the efficacy of this therapy, till when longer duration follow-up studies will not available, it seems to offer a manageable and very efficient way of treating trigeminal pain, constituting a valid alternative to other percutaneous techniques of trigeminal rhizolysis.