The possibilities of treating chronic bronchopneumopathies of various nature by means of permanent endobronchial transcricothyroid probe are examined with reference to 6 cases representing patients under treatment at the time this paper was being prepared (2 cases of chronic pulmonary TB, 2 of suppurating bronchiectasis, 1 of middle lobe syndrome and 1 of tracheal carcinoma). The series examined confirms the usefulness of this type of treatment as a back-up to traditional medical treatment where this alone failed to achieve the necessary results. Stress is laid on the good tolerance of the TCT probe presented by all patients, including a five-year-old boy.