Objective: Gitelman syndrome is a variant of Banter syndrome, characterized by hypokalemia, hypomagnesemia, hypocalciuria, and hypovolemia with metabolic alkalosis. Materials and Methods: We report familial case of Gitelman syndrome ill which one of the siblings presented with hypokalemic periodic paralysis. Result: The proband was a 15year old who presented with recurrent, sudden onset of quadriparesis with the first episode at 8 years of age. He also had short stature, failure to gain weight, and delayed secondary sexual characteristics. He was found to have hypokalemia, hypomagnesemia, metabolic alkalosis, hypocalciuria, and hypermagnesuria. The younger brother, 12 years old, had failure to thrive without weakness and similar biochemical abnormalities. Both responded to potassium chloride and magnesium supplements along with spironolactone. Conclusion: It is worth considering Gitelman syndrome in patients presenting with hypokalemic periodic paralysis by doing serum magnesium level.