Thirty-nine patients were treated with GAX collagen for vocal fold augmentation. The objective results were evaluated by measurement of the maximum phonation time, the phonatory quotient, vocal frequency analysis, and laryngostroboscopy. These results are as good as those with Zyderm Collagen II (ZCI). Avoidance of useless overcorrection, better resistance to collagenase, and less induced hypersensitivity differentiate GAX from ZCI. © 1990, SAGE Publications. All rights reserved.