Background. Esophageal endoscopic ultrasound (EUS) and endobronchial ultrasound (EBUS) are gaining popularity for mediastinal staging of patients with lung cancer. Endoscopic ultrasound and then EBUS were introduced into a single-surgeon thoracic surgical practice. Records were reviewed to determine what effect this had on performance of mediastinoscopy for lung cancer staging, and on discovery of unsuspected N2 disease at the time of resection. Methods. Endoscopic ultrasound and EBUS were introduced 10 months apart. Records were reviewed for the 10 months before EUS (phase 1), the 10 months between EUS and EBUS (phase 2), 8 months after the introduction of EBUS (phase 3), and 11 months after that (phase 4). The number of staging procedures, patients undergoing resection after negative staging, and patients with N2 disease discovered at resection were determined. Results. Two hundred fifty-three patients met inclusion criteria. Eighty-two had resection without staging; staging was positive in 62, negative in 90 who went on to resection, and negative in 19 who had no further evaluation. There was a strong trend toward preferential use of EUS in phase 2 and EBUS in phases 3 and 4. Nine patients (10%) had N2 disease found at surgery: 0 of 16 in phase 1, 4 of 24 in phase 2, 3 of 24 in phase 3, and 2 of 25 in phase 4. Overall sensitivity and negative predictive value of EUS and EBUS were 84% and 87%, respectively. Conclusions. Introduction of EUS and EBUS reduced use of mediastinoscopy. Discovery of N2 disease at surgery was higher than expected initially, but with experience results proved comparable to those of mediastinoscopy. (Ann Thorac Surg 2010;89:885-90) (C) 2010 by The Society of Thoracic Surgeons