Progressive systemic sclerosis and Raynaud's phenomenon are associated with a distinctly vascular form of pulmonary involvement and pulmonary hypertension. To investigate a possible underlying vasospastic predisposition in these patients, the pulmonary vascular response to Raynaud's phenomenon induced by cold-water hand immersion was examined in nine patients. Four patients had pulmonary fibrosis and four patients had the CREST syndrome; no patient had pre-existing pulmonary hypertension. During Raynaud's phenomenon, there was no significant rise in mean pulmonary artery pressure (15 +/- 3 versus 15 +/- 2 mm Hg, p = NS) or pulmonary vascular resistance (112 +/- 38 versus 118 +/- 50 dynes X second X cm-5, p = NS) over baseline, despite a significant rise in mean aortic pressure (104 +/- 14 versus 92 +/- 11 mm Hg, p less than 0.01) and systemic vascular resistance (1,700 +/- 450 versus 1,500 +/- 470 dynes X second X cm-5, p less than 0.01). It is concluded that pulmonary vasospasm with transient pulmonary hypertension does not occur in patients with progressive systemic sclerosis and Raynaud's phenomenon during episodes of Raynaud's phenomenon. Abnormal pulmonary vasospasm in these patients in response to other stimuli, however, is not excluded.