Numerous pathogenic hypotheses were put forward to explain the Funnel Chest. It is possible that the origin of this malformation is not related to an involvement of the thoracic wall or the diaphragm, but rather to a negative pressure behind the sternum which is attracted by inspiratory movements, this resulting in, and aggravating the malformation. This negative pressure of the anterior mediastinum would result from an absent cardiac mass which was displaced leftward, favoured by an enlarged and flaccid pericardial sac. Haemodynamic examination of the subjects with a funnel chest has a two-fold interest: it provides the data for a physiopathologic study. Particularly the measurement of the right ventricular pressure which becomes negative on deep inspiration. On the other hand, it makes it possible to demonstrate the presence or the absence of any cardiac lesion combined with the deformity. The angiographic pictures demonstrate the distortion of the right ventricular chamber in particular, and the elongation of the inferior vena cava. Among the various classical treatments, some aim at cosmetic improvement, others at thoracic wall correction. However, the latter do not prevent recurrence in the child, and are too severe a procedure in the adult. This is why a new treatment is put forward, on the basis of the new pathogenic considerations: repositioning of the cardiac mass displaced leftward, after a pericardoplasty, combined with remodelling of the excavated thoracic wall. Thus cardiac reposition into the anterior mediastinum avoids a long-term recurrence of the deformity. In our experience, pericardioplasty combined with thoracic wall remodelling has given good results, both immediate and delayed, in the two cases in which it was performed. A longer series, particularly on the younger child, is necessary to form an opinion on the value of this procedure.