Compared with the results of a retrospective study (1954) of early detecting bronchial cancer, our present investigations showed, that females are relatively more concerned than formerly, that the climax of frequency has removed for about ten years to the aged, that more non-smokers are concerned than formerly (16% to 3.5% respectively) and that the time between manifestation of the first symptoms and admittance to hospital has shortened remarkably (one month 26%, three months 33% = 59% compared with 28.3%). In four patients the disease has been discovered by x-ray mass-screening, two of them were nevertheless admitted to hospital too late. Whereas the value of tomography has been established, the results of bronchoscopy ameliorated. Only one patient could be operated: perhaps the shift of age for one decade and a certain negative selection may be responsible for these disappointing results. The x-ray-examination in 2 levels must be performed in every adult male patient, even if bronchopulmonal symptoms do not exist. Moreover, exposed persons (e.g. strong smokers) must be controlled by x-ray examination in regular intervals. It is in this sense, that we see the scope of x-ray mass-screening.