In the past decade our understanding of the etiology and pathophysiology of Gitelman syndrome, an autosomal recessive salt-losing tubular disorder with secondary hypokalemia, has increased considerably through the achievements of molecular genetics and cell physiology. In this short review, I will summarize the most recent data on the clinical and biochemical phenotype, the molecular causes, and the pathogenesis of Gitelman syndrome. I will especially focus on the recent elucidation of the mechanisms involved in the pathogenesis of the hypomagnesemia and hypocalciuria that accompanies Gitelman syndrome.