Hypokalemic paralysis is a rare presentation of Fanconi syndrome (FS) caused by Sjögren Syndrome (SS). We describe a 39-year-old man who manifested flaccid paralysis of 4 limbs. Laboratory investigations showed profound hypokalemia (1.6 mmol/L) with renal K wasting, hyperchloremic metabolic acidosis with positive urine anion gap, hypophosphatemia with hyperphosphaturia, hypouricemia with hyperuricosuria, normoglycemic glycosuria, and abnormal serum creatinine concentration 2.2 mg/dL. A thorough survey for the cause of FS revealed that he had xerophthalmia and xerostomia accompanied by high anti-Ro antibody, positive Schirmer test, and delayed saliva excretion on sialoscintigraphy, confirming the diagnosis of SS. Potassium citrate, active vitamin D3, and high phosphate diet for his FS coupled with mycophenolate mofetil for SS resolved clinical symptoms and ameliorated renal function. Early recognition of HP due to the underlying SS-related FS with prompt therapy not only could terminate potentially life-threatening hypokalemia, but also improve renal outcome.