For the treatment of facial paralysis, functioning free muscle transplantation has become accepted standard treatment. Choice of donor nerve and number of surgery stages, however, are still matters of great debate. Between 2000 and 2011, 36 patients (out of 329; 11 percent) with 42 functioning free muscle transplantations were treated using spinal accessory nerve (XI)-innervated muscle for facial reanimation as a one-stage procedure. Indications included bilateral or unilateral Möbius syndrome, severe postparetic facial synkinesis, and patient preference. Postoperative smile training was required to achieve spontaneous smile. For outcome assessment, patients were evaluated using multidisciplinary methods, including objective smile excursion score (range, 0 to 4), cortical adaptation stage (range, I to V), tickle test, and subjective patient questionnaire and satisfaction score (range, 1 to 5). Mean smile excursion score improved from 0.5 preoperatively to 3.4 postoperatively. Eighty-three percent of patients were able to perform independent and even spontaneous smile after 1 year of follow-up. Ninety percent of patients had a mean satisfaction score of 3.4 out of 5. However, 50 percent expressed more concern with aesthetic appearance than functional status. There was no functional morbidity of the donor shoulder in daily life. The classic two-stage procedure is still the first choice for facial paralysis reconstruction. However, the effectiveness of XI-innervated free muscle for facial reanimation in a one-stage procedure has proven it to be a good alternative treatment. It has become second in popularity for facial paralysis reconstruction in the authors' center. Therapeutic, IV.