Pulmonary involvement is one of the most common extra-articular manifestations of rheumatoid arthritis (RA). The aim of this prospective study was to assess pulmonary involvement with high resolution computerized tomography (HRCT) in lifelong non-smoking patients with RA. Twenty-six female and eight male patients with a mean age of 45.26 +/- 11.6 years and without any evidence or symptoms of a respiratory disease were included in the study. Data were obtained regarding duration of disease, clinical symptoms and disease activity parameters. Standard chest roentgenographs, pulmonary function tests (PFT) and HRCT were performed. PFT was abnormal in eight (23.5%) and HRCT was abnormal in 23 patients (68%). The most frequent abnormalities obtained on HRCT were interstitial involvement including septal and peribronchial thickening and fibronodular infiltration, which were found in 23 patients, and bronchiectasis was found in nine patients. Using a highly sensitive technique such as HRCT the incidence of pulmonary abnormalities in asymptomatic rheumatoid patients may be much higher than previously reported.