A 24-year-old man had several episodes of hypokalemic muscle weakness of undetermined etiology since the age of 13 years. Wilson's disease (WD) was not diagnosed until the age of 18 when wing-beating tremor in the left upper limb was noted. Renal function study revealed incomplete proximal renal tubular acidosis. The hypokalemic muscle weakness and wing-beating tremor had subsided after long-term penicillamine therapy. The present case indicates that recurrent hypokalemic paralysis due to renal tubular acidosis is a rare initial presentation of WD and may respond to penicillamine therapy.