Objective: To investigate the e ect of subclinical hyperthyroidism on voice quality using acoustic analysis. Study Design: Cross-sectional comparative study. Place and Duration of the Study: Department of Endocrinology and Metabolism, Ankara Diskapi Yildirim Beyazit Research and Education Hospital, Ankara, Turkey, from January to June 2020. Methodology: A total of 115 participants, with 60 patients with subclinical hyperthyroidism and 55 healthy volunteers, were evaluated and compared. Healthy volunteers with similar age and gender distributions were also evaluated and compared. Acoustic variables including average fundamental frequency (F0), relative average perturbation (RAP), jitter, shimmer, noise-to-harmonic ratio (NHR), and voice turbulence index (VTI) were measured and recorded. Results: In the patient group, acoustic voice analysis results were obtained for 0F224.97%, jitter 0.85%, RAP 0.51%, shimmer 3.16%, NHR 0.12 dB, and VTI 0.047, respectively. In the control group, these respective values were 219.60%; 0.74%; 0.46%; 3.11%; 0.12 dB; and 0.045, respectively. There was no statistically signi cant di erence between the groups (p>0.05). Conclusion: Subclinical hyperthyroidism does not cause a signi cant change in voice quality.