The results obtained in 47 percutaneous cordotomies performed in 43 patients are reported. The methods used, the anatomic references, the radiologic and neurophysiology controls are described and commented. No diference was observed in the results if we consider the type and duration of the pre-existing pain, as well as the previous presence of sensory deficit. The benefits and complications of such form of treatment are described and compared with the ones presented in the literature, being equivalent. The study of this cases permit to conclude that this form of treatment is useful, causes little trauma and is well tolerated by patients in poor general conditions. The performance of the lesion with the patient awake adds the advantage of permitting a better control of the immediate results.