The association of clinical and serologic features of 34 patients with systemic sclerosis was examined. Anti-Scl 70 antibody was found to identify patients with abnormal pulmonary function, particularly impaired diffusion (p less than 0.005), as well as patients with digital pitting scars (p less than 0.025). In addition, the presence of digital pitting scars correlated with impaired diffusion (p less than 0.005), suggesting that interstitial pulmonary disease in systemic sclerosis may, like digital pitting, be secondary to vascular pathology. Anticentromere antibody-positive patients were less likely to have abnormalities of pulmonary function (p less than 0.001).