Guillain-Barré syndrome, an acute autoimmune polyneuropathy and demyelinating disease, is characterized by weakness, sensory loss, areflexia, pain, autonomic dysfunction, and occasionally, micturition disturbances including voiding difficulty, urinary retention, nocturnal urinary frequency, and urge incontinence. Typically, urinary dysfunction resolves simultaneously with other neurologic deficits. We report the case of a 20-year-old woman with Guillain-Barré syndrome and persistent urinary retention 18 months following initial diagnosis. This patient is the first described in the literature to undergo successful treatment with sacral neuromodulation. Immediately following neuromodulator placement, the patient voided spontaneously and has had no voiding dysfunction or postvoid residual after 5 months of follow-up.