Progressive systemic sclerosis (PSS) is a connective tissue disease characterized by fibrosis and thickness of cutis and subcutis (scleroderma) and deterioration of small arteries and capillary vessels, with changeable visceral renal, cardiac, intestinal and pulmonary involvements. The disease is characterized by cutaneous sclerosis, that is to say by the increase of consistence and thickness of cutis that lose her usual elasticity. The sclerosis can be limited to the fingers (sclerodactyly) or can involve otherwise (acrosclerosis); many other time is diffuse also to upper limbs and to thorax (diffuse scleroderma). The disease is rare and its incidence is variable from 2 to 10 x 10(6); more frequently hits women than men in the ratio of 3 to 1 or 8 to 1 (according to certain Authors). In the elderly is more frequently represented by the CREST syndrome (calcinosis, Raynaud's phenomenon, oesophageal dismotility, sclerodactyly, teleangiectasia). The authors have considered nine patients with pulmonary involvement of progressive systemic sclerosis: five with CREST syndrome and four with diffuse scleroderma. In addition to the common routine examinations, we performed chest radiography (CXR), pulmonary function tests, fiberoptic bronchoscopy and bronchoalveolar lavage (BAL), Gallium 67 scanning and high resolution computed tomography (HRCT) with the purpose to consider the role of these medical examinations in diagnosis and the follow-up of pulmonary involvement in scleroderma. From the results we have observed that: 1) in early disease chest radiography may be silent even if the patient shows a restrictive syndrome and reduction of diffusion capacity of carbon monoxide (DLCO); 2) chest radiography, pulmonary function tests and Gallium 67 scanning have traditionally been used to measure the degree of lung involvement in SSP but unfortunately, none of these reliably predicts disease activity or future course; 3) bronchoalveolar lavage shows the degree of lung inflammation (alveolitis) characterized by the increase of total BAL cell counts and by higher neutrophil cells in the initial stage of the disease; 4) even HRCT shows in this stage, the typical aspect of higher endoalveolar cellularity with ground glass appearance. With the progression of anatomical damage, there can be found even appearance of complete destruction of pulmonary architecture with the typical alteration of honeycomb. These findings support the hypothesis that a ground glass appearance on HRCT is the radiographic equivalent of alveolitis found in BAL. Furthermore HRCT shows itself useful in the follow-up the disease and in detecting of its activity condition.(ABSTRACT TRUNCATED AT 400 WORDS)