Pulmonary function abnormalities constitute the most important cause of mor
bidity and mortality in patients with systemic sclerosis (SSc). A restricti
ve ventilatory defect with a reduction in pulmonary carbon monoxide diffusi
on capacity (DLCO) is the commonest finding. Static lung compliance (Cst) i
s perhaps the most sensitive parameter for the detection of abnormal pulmon
ary mechanics. We compared the results of Cst and DLCO in patients with SSc
and normal spirometry to identify early pulmonary disease. Sixteen of 50 p
atients had normal spirometry, eight of whom had abnormal Cst. Four of them
also had a reduced DLCO. Two patients had abnormal DLCO but their Cst was
normal. One of them had pulmonary hypertension on echocardiography. We conc
lude that Cst was helpful in diagnosing early pulmonary abnormality in 50%
of patients with normal spirometry. Among these patients Cst was a better i
ndex of abnormality than DLCO.