The advent of endoscopic ultrasound has allowed excellent visualization of the mediastinum, particularly the left-sided mediastinal lymph nodes and the subcarinal space. The procedure itself is nothing more than an upper endoscopy with a special endoscope that has a real-time ultrasound probe attached. The procedure takes anatomic advantage of the fact that the esophagus lies posteriorly and to the left of the trachea and is in the proximity of the lymph nodes between these two structures. Lymph node level 5 (aortopulmonary window), level 7 (subcarina), and inferior mediastinal lymph nodes are particularly easy to access by this method. In the past, the aortopulmonary window would have required an extended cervical mediastinoscopy or a left anterior mediastinotomy (Chamberlain procedure), and thoracoscopy is required for posterior subcarinal and inferior nodes. Once the lymph node in question is visualized, a needle can be passed in real-time and cytologic tissue can be obtained. EUS-FNA can be performed in the outpatient setting with conscious sedation, and the complication rate is virtually nil. As in the article published within this issue, others have reported similar results with EUS-FNA in lung cancer.3–5 The only downside to this technology is the inability to access the right side (levels 2R, 4R) and the pretracheal space. In addition to the ability to visualize and sample enlarged lymph nodes, EUS-FNA has the ability to detect malignancy in normal-sized lymph nodes. EUS-FNA in patients without discernable lymphadenopathy was initially reported by Devereaux et al6 to change the TNM stage in 18% of patients, and was reported to have a sensitivity of only 35%. A subsequent study by Wallace and colleagues5 showed a change in stage in 42%. This variability is explained by the techniques used. The higher-yield study obtained samples from any and all levels in which a node was seen, regardless of the lymph node characteristics. This change in technique does prolong the procedure, and further work is being done with computer modeling to determine if there are characteristics of lymph nodes that should guide fine-needle aspiration.