Sweat-chloride levels at the time of diagnosis have been reviewed from 708 patients with cystic fibrosis. Sixty-one patients, shown to be non-steatorrheic, were found to have significantly lower levels than 647 patients with severe pancreatic insufficiency. Although patients who retain pancreatic function are known to have less severe pulmonary involvement and a better overall prognosis (5), we were unable to show any correlation of sweat-chloride levels at diagnosis with pulmonary function, current age or Shwachman clinical score which might be of prognostic value.