Sodium is an important cation and has an important role in BP regulation and ECF balance. Kidney plays an important role in sodium balance. Almost 99% of filtered sodium is reabsorbed. The absorption occurs via sodium transporters located in the various segments of the nephron. Each of these transporters has unique features and is blocked by a specific diuretic. The activating and inactivating mutations of these transporters are associated with important clinical syndromes. The understanding of these transporters and their mutations is essential for proper diagnosis and management of syndromes associated with the defects of these transporters. Also the knowledge of sodium transporters helps in understanding the role of kidney in pathogenesis of hypertension and pharmacodynamics of diuretic action.