A controllable brush and a new controllable guide wire have been developed for selective bronchial catheterization and bronchial brush biopsy. The technique for using these instruments is described. This system offers 2 principal advantages over previous methods: it decreases the average time required for the examination; and it extends the range of the procedure to include otherwise inaccessible peripheral lesions. With these instruments, it is possible to brush any visible lesion anywhere in the bronchial tree.