Introduction: The larynx development is sensitive to endocrinological changes, mainly to sex hormone. If these changes occur at the time of puberty, larynx and voice are permanently altered. In Congenital Adrenal Hyperplasia there is a high level of cortisol and androgens which produces masculinization and infertility in female. Androgens cause irreversible virilization of the larynx and voice. This disease can be controlled by corticosteroids, although larynx changes can not be reverted. In these cases surgical procedures are necessary, such as Isshiki’s thyroplasty type IV to increase fundamental voice frequency. Objective: To present a female patient with low fundamental frequency of the voice, as a result of congenital adrenal hyperplasia, submitted to surgical procedure to increase the fundamental frequency of her voice. Case report: A female, 16-year-old patient with congenital adrenal hyperplasia controlled by medication had strong psychological negative effects due to the low fundamental frequency of her voice. After Isshiki’s thyroplasty type IV, her voice improved, but a voice therapy was necessary to adapt her voice and increase its range. Conclusion: In this case, Isshiki’s thyroplasty type IV was an effective therapeutic method.