Bartter syndrome is a rare, salt-wasting tubulopathy with impaired ion reabsorption in the ascending limb of the loop of Henle, which results in hypokalemia, hypochloremia, and hypercalciuria. It usually presents in neonates, with vomiting, dehydration, and failure to thrive. It results from mutations in several genes, including KCNJ1, CLCNKB, CLCNKA, BSND, and ROMK, which encode ion transporters. We report a rare presentation of adult-onset Bartter syndrome. In this case, a 27-year-old man presented to the hospital with upper and lower limb weakness. Bartter syndrome was suspected based on serum electrolytes assessment and arterial blood gas analysis. The patient was initiated on potassium chloride (KCL) infusion and potassium chloride syrup to correct hypokalemia.