High-resolution computed tomographic (HRCT) scans and chest radiographs were obtained in 23 patients with progressive systemic sclerosis (PSS) to assess the diagnostic merits of HRCT compared with chest radiography in detecting interstitial lung involvement in these patients. HRCT scans showed interstitial disease in 21 patients (91%). The most frequent finding was the so-called subpleural lines, which were demonstrated in 17 patients (74%). Honeycombing was seen in seven patients (30%), while parenchymal bands were seen in six patients (26%). Chest radiographs, on the other hand, showed definite interstitial opacification patterns in only nine patients (39%); six patients (26%) had equivocal reticular areas of attenuation, while eight patients (35%) had normal chest radiographs. Thus, HRCT is much more sensitive than chest radiography when assessing minimal interstitial lung involvement in patients with PSS.