The role of echography in the study of the thorax is evaluated: after reporting the technical limits due to the peculiar anatomy of this region, personal experience is presented. This method extremely precise to define the solid or liquid nature of tightly adherent to the chest wall lesions, but it is non specific to assess their benign or malignant behaviour. Ultrasounds have their on limits in drawing the extension of such lesions; these limits have been overcome by CT and MR. Finally the usefulness of the method in studying the diaphragm and its pathology is briefly described.