In this investigation, we evaluated the effectiveness of surface electromyography (EMG) biofeedback to treat paradoxical vocal fold motion in a 16-year-old girl. EMG biofeedback training occurred once per week over the course of 10 weeks. In a changing criterion design, muscle tension showed systematic changes that corresponded with changes in the criterion. Overall, baseline muscle tension levels were reduced over 60%, with corresponding reductions in episodes of respiratory distress and chest pain. Subjective reports by the patient and the patient's mother indicated improvements in school attendance and overall adaptive functioning.