Behçet disease is a multisystem vasculitis characterized by mucosal aphthosis, primarily in the oral and genital mucosa. Only a few cases of involvement of the nasal mucosa have been reported in the literature, and its true prevalence is not known. We conducted a cross-sectional study of 400 consecutively presenting patients with confirmed Behçet disease (according to classification-tree criteria) to determine the incidence of nasal mucosal involvement, to identify its particular characteristics, and to determine if there are any statistically significant differences in clinical and paraclinical parameters between Behçet disease patients with nasal involvement and those without. To the best of our knowledge, this is the first systematic evaluation of nasal involvement in patients with Behçet disease to be published in the literature. Data analysis was performed with Statistical Package for the Social Sciences software (SPSS), and a confidence interval (CI) at 95% was calculated for each finding. Involvement of the nasal mucosa was seen in 31 of the 400 patients (7.8%; CI: 5.1 to 10.5). Among those 31 patients, the most common nasal symptom was dysosmia, which was seen in 15 patients (3.8% of the total population; CI: 1.9 to 5.7); other nasal symptoms included obstruction in 10 patients (unilateral in 9), ulcers in 2, pain in 2, and a burning sensation and discharge in 1 each. No patient reported a history of epistaxis or nasal itching. Abnormal signs were present in only 16 patients (4.0%; CI: 2.1 to 5.9); they included nasal cartilage deformity in 6, unilateral nasal obstruction in 4, postnasal discharge in 3, nonaphthous ulcer in 3, and crusted ulcer in 2 (2 patients each had 2 abnormal signs). No case of aphthous ulcer, nasal discharge, nasal scar or deformity, septal perforation, or nodular or granulomatous cartilage lesion was found. There were no statistically significant differences in clinical and paraclinical disease manifestations between those patients who had nasal mucosal involvement and those who did not.