Collagen-vascular disorders (CVD) are commonly associated with chronic interstitial lung disease. Clinicopathologic observations suggest that inflammatory process of the lower respiratory tract may appear prior to fibrosis. Subclinical pulmonary involvement, as assessed by bronchoalveolar lavage (BAL) was evaluated in 61 patients with various CVD but free of clinical pulmonary symptoms and with normal chest roentgenograms. Eight of 61 had abnormal pulmonary function tests (PFT) at entry to the study. Total BAL cell yield from nonsmokers was greater in patients with abnormal than in those with normal PFT (p less than 0.05). Abnormal differential count of BAL cells was noted in 29 of 61 patients (48%). Lymphocyte alveolitis (lymphocytes greater than or equal to 18%) was a characteristic finding in patients with primary Sjögren's syndrome (11 of 25) or Sjögren's syndrome associated with another CVD (4 of 8). Neutrophil alveolitis (neutrophils greater than 4%) with or without increased percentage of lymphocytes occurred in patients with CVD classically associated with pulmonary fibrosis: progressive systemic sclerosis (6 of 10), rheumatoid arthritis (1 of 4), dermatopolymyositis (2 of 3), and mixed connective tissue disease (3 of 8). An increased percentage of eosinophils was detected in 1 patient with progressive systemic sclerosis. Bronchoalveolar lavage abnormalities were more frequently detected in patients with active and severe extrapulmonary disease. On follow-up PFT 12 months later, 11 patients with normal BAL and 10 patients with lymphocyte alveolitis had not deteriorated. In marked contrast, the presence of neutrophils in BAL was associated with a progressive deterioration of PFT in 6 of 7 untreated patients, whereas 4 corticosteroid-treated patients with neutrophil alveolitis had not deteriorated.(ABSTRACT TRUNCATED AT 250 WORDS)