Isosorbide dinitrate, ISDN, is a nitrate used pharmacologically as a vasodilator for angina (heart-related chest pain), congestive heart failure, and esophageal spasms.

Isosorbide dinitrate is sold in the USA under the brand names Dilatrate-SR by Schwarz and Isordil by Valeant, according to FDA Orange Book. In the United Kingdom, Argentina, and Hong Kong, a trade name of it is Isoket. It is also a component of BiDil. It is on the World Health Organization's List of Essential Medicines, the most important medications needed in a basic health system.