Unilateral vocal fold paralysis causes glottic incompetence and can result in significant morbidity. To prevent such morbidity, surgeons treat affected patients with vocal fold medialization techniques; type I thyroplasty medialization surgery is widely used for this purpose. In this procedure, a window is opened on the thyroid cartilage to allow for placement of a silicon prosthesis to medialize the vocal fold. A 38-year-old woman presented to our clinic for evaluation of hoarseness and a low-pitched voice, which we diagnosed as being caused by left vocal fold paralysis. Two years earlier, she had undergone a thyroidectomy for the treatment of benign thyroid disease. One year after that, she underwent type I thyroplasty medialization surgery at another center. During that operation, the surgeon had mistakenly created the window on the cricoid cartilage rather than the thyroid cartilage. When he inserted the silicon prosthesis into the cricoid window, the patient developed acute respiratory obstruction. At that point, the prosthesis was removed and the operation was terminated. One year later, she presented to us, and we performed a revision type I thyroplasty. Intraoperatively, we discovered that the original window had been opened on the cricoid cartilage instead of the thyroid cartilage, which was intact. We left the cricoid window untouched, opened a new window on the thyroid cartilage, and completed the type I thyroplasty in the usual fashion. The patient's postoperative recovery was uneventful, and she was doing well at 5 years of follow-up. To the best of our knowledge, no case of a thyroplasty window being opened on a cricoid cartilage has been reported in the literature.