Gitelman’s syndrome(GS) is a salt-losing tubulopathy with an autosomal recessive inheritance caused by mutations of SLC12A3, which encodes for the thiazidesensitive Na Cl cotransporter. In this study we report a new mutation of SLC12A3 found in two brothers affected by GS. Hypokalemia, hypocalciuria and hyperreninemia were present in both patients while hypomagnesemia was detected only in one. Both patients are compound heterozygotes carrying one well known GS associated mutation(c.2581 C > T) and a new one(c.283 del C) in SLC12A3 gene. The new mutation results in a possible frame-shift with a premature stopcodon(pG ln95 Argfs X19). The parents of the patients, heterozygous carriers of the mutations found in SLC12A3, have no disease associated phenotype. Therefore, the new mutation is causative of GS. Gitelman’s syndrome (GS) is a salt-losing tubulopathy with an autosomal recessive inheritance caused by mutations of SLC12A3, which encodes for the thiazidesensitive Na Cl cotransporter. In this study we report a new mutation of SLC12A3 found in two brothers affected by GS. Hypokalemia , hypocalciuria and hyperreninemia were present in both patients while hypomagnesemia was detected only in one. Both patients are compound heterozygotes carrying one well-known GS associated mutation (c.2581 C> T) and a new one (c.283 del C) in SLC12A3 The new mutation results in a possible frame-shift with a premature stop codon (pG ln95 Argfs X19). The parents of the patients, heterozygous carriers of the mutations found in SLC12A3, have no disease associated phenotype. Thus, the new mutation is causative of GS.