Ear, nose, and throat (ENT) lesions are frequently involved in Stevens-Johnson syndrome and toxic epidermal necrolysis (SJS/TEN), although a detailed description is lacking in the literature. To describe ENT lesions at the acute stage and follow-up in a large series of patients with SJS/TEN and identify factors associated with the severe ENT form. Retrospective study of 49 patients with SJS/TEN hospitalized in a referral care center from 2005 to 2010. Patients who underwent a full ENT workup including examination and a nasal fiberoptic endoscopy by an otorhinolaryngologist in the acute phase and during follow-up at 2 and 12 months were included in the study. Recorded variables included maximal body surface area (BSA) detachment, SCORTEN (Score of Toxic Epidermal Necrosis [a severity of illness score]), sites and type of ENT mucosal lesions, intensive care unit transfer, pulmonary infection, and mortality. "Severe ENT form" was defined by the occurrence of laryngeal lesions with the risk of airways obstruction. Clinical characteristics associated with severe ENT form were analyzed in univariate and multivariable analysis. Of the 49 patients who underwent a full ENT workup (female to male ratio, 1.1:1), ENT symptoms (eg, odynophagia, dysphagia, dysphonia, dyspnea, earache, nasal obstruction) occurred in 48 (98%). Dyspnea or dysphonia were significantly associated with severe ENT form (21% [P = .03] and 50% [P < .001], respectively). Topographic frequencies of lesions were as followed: lips and oral cavity (n = 46 [93%]) and pharynx and vestibule of the nose (n = 26 [53%]). Fourteen patients (29%) had severe ENT form. Findings for other recorded variables for those with vs without ENT examination are as follows: maximal BSA detachment (20% [0%-95%] vs 5.5% [0%-95%]; P = .004), SCORTEN (1 [0-5] vs 1 [0-5]; P = .54), intensive care unit transfer (10 [20%] vs 9 [19%]; P = .80), pulmonary infection (9 [18%] vs 6 [13%]; P = .10), and mortality (3 [6%] vs 5 [10%]; P = .70). In multivariable analysis, pulmonary infection was significantly associated with severe ENT form (odds ratio, 5.9 [95% CI, 1.1-32.8] [P = .04]). After remission of SJS/TEN, a complete ENT mucosal healing occurred in 36 patients (74%) at 2 months and in nearly all patients (n = 48 [98%]) at 1 year of follow-up. Severe ENT form is associated with pulmonary infection and is easily detected by nasal fiberoptic endoscopy. ENT evaluation should be suggested when dysphonia or dyspnea is observed at the acute stage of SJS/TEN.