Pulmonary hypertension has been reported rarely in patients with systemic lupus erythematosus (SLE). During the past 31/2 yr we have observed pulmonary hypertension as a major clinical manifestation of their disease in four of 43 patients with well-documented SLE followed at out institution. Pulmonary hypertension could be attributed to underlying lung disease in three and was considered to be primary in the remaining patient. Neither hydralazine nor prednisone administration had any effect on the course of the pulmonary hypertension in these patients. The presence of pulmonary hypertension in the course of active SLE may be more common than previously recognized.