Objective: Arytenoid adduction (AA) surgery can be technically challenging, potentially limiting its utilization in general practice. Since AA often serves as an adjunct to thyroplasty type I (TTI) in the management of unilateral vocal fold paralysis (UVFP), this study sought to define the anatomic position of the muscular process (MP) of the arytenoid cartilage in relation to the TTI window and other key thyroid cartilage landmarks, thereby facilitating a more efficient surgical approach. Study Design: Cadaveric anatomic dissections. Methods: Arytenoid MPs were identified bilaterally in eight cadavers for a total of 16 hemilarynges. The location of the MP was measured relative to the anteroinferior corner of the traditional TTI window and also relative to the roots of the superior and inferior cornua for comparison with other studies. Results: The muscular processes were located along an axial line extending posteriorly from the inferior border of the TTI window and parallel to the inferior border of the thyroid cartilage. In males, the mean distance to the MP was 26.9 mm from the anteroinferior corner of the window, while in females the mean distance was 18.9 mm. In all cases, the MP was inferior to the midpoint between the roots of the superior and inferior cornua (mean inferior offset = 2.7 mm). Conclusion: The TTI window can be used intraoperatively to help locate the arytenoid muscular process during arytenoid adduction surgery.