OBJECTIVE: To investigate the relationship the electrodiagnostic findings with the functional outcomes in spina bifida patients and to assess usefulness of follow up electrodiagnostic study. METHOD: Initial and follow up electrodiagnostic data of 100 patients who had been diagnosed as spina bifida were obtained retrospectively. Electrophysiological diagnosis and neurological level were investigated by the findings of needle electromyography. Each patients were divided into no change, improvement and deterioration group according to follow up study. The change of urodynamic study findings and clinical findings were also investigated. The recent functional outcomes and the presence of complications were evaluated by recent outpatient record. RESULTS: 56 patients had no change, 15 patients had improvement and 29 patients had deterioration electrophysiologically. The initial electrodiagnostic findings were associated with the functional outcomes in patients with spina bifida (p<0.05). However, neurological level by electrodiagnostic findings cannot predict functional outcomes except ambulation activities. The change of electrodiagnostic findings of follow up study were related with the change of clinical findings statistically (p<0.05). CONCLUSION: Follow up electrodiagnostic study as well as initial study is necessary for the evaluation of the change of neurological states in the patients with spina bifida.