We report a case of hypokalaemic quadriparesis in 31-year old woman in whom the discovery of distal renal tubular acidosis led to the diagnosis of primary Sjögren's syndrome. Hypokalaemic paralysis as initial manifestation of primary Sjögren's syndrome is rare, but when it occurs it may precede symptoms of xerostomia and xerophthalmia. The diagnosis of primary Sjögren's syndrome should be considered in young women who present with progressive weakness, hypokalaemia and metabolic acidosis.