Objective-The present study assessed the diagnostic and prognostic signifi- cance of endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) for suspected intrathoracic metastasis after HNC treatment.Methods-A retrospective analysis was conducted on 75 patients with a prior history of head and neck cancer treatment who underwent EBUS-TBNA for suspected intrathoracic metastases between March 2012 and December 2021.Results-A total of 126 targeted lesions, including 107 mediastinal/hilar lymph nodes and 19 intrapulmonary/mediastinal masses, were sampled. The metastatic head and neck cancer (HNC) cases detected by EBUS-TBNA consisted of nasopharyngeal carcinoma (n = 24), oropharyngeal carcinoma (n = 3), hypopharynx carcinoma (n = 6), laryngeal carcinoma (n = 6), and oral cavity carcinoma (n = 6). Cases with negative EBUS-TBNA results consisted of tuberculosis (n = 9), sarcoidosis (n = 3), anthracosis (n = 9), and reactive lymphadenitis (n = 9). Six false-negative cases were found among the 75 patients with suspected intrathoracic metastases. The diagnostic sensitivity, specificity, positive predictive value, negative predictive value, and diagnostic accuracy of the EBUS-TBNA procedure for metastatic HNC were 88.2, 100.0, 100.0, 80, and 92.0%, respectively. The diagnosis of HNC intrathoracic metastasis by EBUS-TBNA correlated with an adverse prognosis in terms of overall survival (OS) (P = .008). The log-rank univariate analysis and Cox regression multivariate analysis results indicated that the detection of metastatic HNC through EBUS-TBNA was a significant independent prognostic factor for patients with HNC who had received prior treatment. Conclusions-Endobronchial ultrasound-guided transbronchial needle aspiration is a safe, effective, and minimally invasive procedure for assessing suspected intrathoracic metastasis in HNC patients after treatment. The intrathoracic metastasis detected by EBUS-TBNA has crucial prognostic significance in previously treated HNC patients.