Practical aspects of Storz Dlight autofluorescence bronchoscopy are presented from a series of 73 patients. 80 biopsies were taken of which 23 had at least moderate dysplasia, including 8 CIS lesions. Causes of false positive fluorescence abnormalities were suction trauma, overlying mucus, depressions in the leading edge of bronchial spurs, and flexion points of spurs. Positive predictive value of a significant fluorescence abnormality was 56%. The highest yield was in those patients with prior ENT malignancy.