Rapid development of endothelin (ET)-receptor antagonists by the pharmaceutical industry reflects the potential therapeutic significance of these agents. The primary therapeutic indication for ET-receptor antagonists has been congestive heart failure, and recent clinical data support a role for these novel agents in the treatment of this indication.*However, development of potent and selective endothelin antagonists has helped in the identification of other diseases in which this peptide may also play an important role. Pulmonary hypertension and perhaps asthma are leading contenders in the list of diseases likely to benefit from clinically effective, orally active ET-receptor antagonists, delegates were told at the International Conference of the American Lung Association and the American Thoracic Society [Chicago, US; April 1998].