In a patient with bronchogenic carcinoma, a transbronchial needle aspiration of subcarinal and paratracheal lymph nodes was performed for purposes of staging. On cytologic examination of the specimen, a clump of malignant cells was found; however, subsequent mediastinoscopy and thoracotomy showed no evidence of metastases to mediastinal lymph nodes. We postulate that specimens from transbronchial needle aspiration can be contaminated with tumor cells located on the airway surface epithelium.