Some early studies have called attention to the potential contribution of sodium (both dietary and serum levels) in airway-related disease, although the picture was not entirely clear. Two recent developments may now allow a more careful consideration of this: first, the greatly improved understanding of the role of salt in hypertension (particularly the identification of sub-groups of salt-sensitive individuals within the general population), and the recent discovery of the role of the Na⁺/Ca²⁺-exchanger in smooth muscle function. Here, we first review those two developments, and then apply them to airway smooth muscle and asthma.