Objectives: The purpose of this study is to investigate the feasibility of using an injectable needle electrode to guide hyaluronic acid (HA) vocal fold injection (VFI) during laryngeal electromyography (LEMG) for unilateral vocal fold paralysis (UVFP). Study Design: Prospective study. Methods: From March to June 2010, 20 UVFP patients received LEMG examination at our clinic. Before completion of LEMG, 1.0 cc of HA (Restylane Perlane; Q-Med, Uppsala, Sweden) was injected via a 26-gauge monopolar injectable needle electrode into paralyzed thyroarytenoid muscle. After injection, 20 patients completed 3-months follow-up and 16 patients completed 6-months follow-up. The data before, 1 week, 3 months, and 6 months after injection, including the normalized glottal gap area (NGGA) from videostroboscopy, maximal phonation time (MPT), mean airflow rate (MAFR), phonation quotient (PQ), perceptual evaluation of voice (grade, roughness, breathiness, asthenia, strain [GRBAS] scale), Voice Handicap Index (VHI), and self-grading of choking (grade 1-7), were analyzed by the Wilcoxon signed rank test. Results: All of the patients completed the procedure without complications. After injection, mean NGGA was significantly reduced from 8.28 units to 0.52 units (1 week), 1.79 units (3 months), and 1.36 units (6 months). The mean MPT was prolonged from 5.66 seconds to 11.73, 11.25, and 11.93 seconds, respectively. VHI was reduced from 76.05 to 38.10, 37.40 and 35.00, respectively. Other analyzed data (PQ, MAFR, GRBAS scale, and choking severity) also showed statistically significant improvement. Conclusion: LEMG-guided HA VFI provides UVFP patients with neuromuscular function evaluation and treatment in one step. This clinical technique is feasible, and the short-term results are satisfactory.