From 1976 to 1990, 140 patients (mean age, 66 years; 91% male) underwent repeat mediastinoscopy as a routine staging procedure. The mean interval between first and second mediastinoscopy was 56 months. Owing to adhesions, 26 repeat mediastinoscopies (18%) were considered incomplete. There was no mortality, and 10 complications did not require interventional therapy. The results were positive in 20 patients, thus avoiding an unnecessary thoracotomy. In 7 patients with negative findings, positive lymph nodes were found at thoracotomy or by transcarinal puncture biopsy. The sensitivity of repeat mediastinoscopy in this series is 74%, and the accuracy 94%. We consider repeat mediastinoscopy a safe and reliable preoperative staging procedure in new or recurrent lung cancer.