Lung involvement in children affected with Systemic Sclerosis (SSc) has been studied. We used ventilation and perfusion scans and compared the results to those obtained with traditional pulmonary function tests. The vascular pulmonary area was examined with a gama-camera after infusion of 99mTc microspheres, while the alveolo-capillary membrane and the airways were investigated after administration of a radioaerosol, (99mTc DTPA). Pulmonary function tests revealed either alteration of the airways or a considerable involvement of the alveolo-capillary membrane in two patients. On the other hand ventilation scan showed airways alterations and a severe decrease of the alveolocapillary permeability in all patients. Our study indicates that ventilation scans may be useful in the diagnosis of early modifications of the lung function also in paediatric age and may complement the data obtained from traditional function tests.