Head and neck (H&N) cancer patients have a high incidence of second primary tumors in the tracheobronchial tree. Diagnostic autofluorescence endoscopy (DAFE) has shown promising results in the detection of early neoplastic and pre-neoplastic changes in the bronchi. We have investigated the medical impact of DAFE in a population of H&N cancer patients. The bronchoscopies were performed using a modified commercially available DAFE system, allowing both white light (WL) and autofluorescence (AF) bronchoscopy. Endoscopic imaging of the tissue AF was combined with an online image analysis procedure allowing to discriminate between true and false positive results. Twenty-one H&N cancer patients with a high risk of bronchial cancer underwent WL and AF bronchoscopy with this improved system. Forty-one biopsies were taken on macroscopically suspicious (WL or AF positive) bronchial sites. Histopathologic analysis confirmed pre- or early neoplastic changes in 11 of these biopsies taken from 8 patients. The sensitivity for the detection of these early lesions with the DAFE was 1.6 times larger than the sensitivity of WL bronchoscopy only. The positive predictive value (PPV) for AF was 79% (33% for WL alone). The PPV of both methods together was 100%. DAFE proved to be efficient for the detection of second primary lesions in H&N cancer patients. It can thus be used as a simple additional procedure to pre-operative or follow-up examination in this patient population. ©2007 SPIE-OSA.