Pyridoxine has been known as an essential cofactor in many important biological reactions of tissue metabolism including blood, skin, and central nervous system. Nowadays, vitamins are widely consumed because of the belief that they provide health benefits with no harm. We report a patient with sensory ataxia who had a 3-year history of excessive vitamin B6 intake. Her clinical and electrodiagnostic findings were characteristic of sensory neuronopathy, which were probably caused by pyridoxine intoxication. Physicians should be aware of the toxicities of megavitamin therapy.