목적: To asess the incidence of thyroid gland involvement, factors favoring TGI,indications of hemithyroidectomy, and postoperative complications. 방법:It is a prospective analytical study that was performed at theotorhinolaryngology department, Kasr El Aini Hospital, Cairo University. It included 40 patientswho were diagnosed T 3 or T 4 laryngeal carcinoma and candidate for total laryngectomy withat least hemithyroidectomy. Statistical analysis was carried out to determine the incidence ofthyroid gland invasion histopathologically in laryngeal carcinoma and to correlate it with siteand stage of the primary tumor vocal cord fixation, subglottic extension, and prior radiation 결과:Our study included 40 patients 37 were males. We found 4 cases (10%) had thyroidgland invasion by laryngeal carcinoma all were males (100%), two cases (5%) had colloidalnodules and one case (2.5%) had follicular adenoma. Thyroid cartilage invasion was evident inall 4 cases (100%) with TGI. That was of statistical significance. Postoperative complicationsoccurred in 28 cases (45%). Three cases with TGI (75%) develop complications. Hist 결론:ological TGI by advanced tumours must not be underestimated. Subglottic and transglottictumors are more prone to TGI. Thyroid cartilage invasion and preoperative CT findings ofthyroid gland were statistically correlated with TGI.