This was a prospective observational study nested within the Pan-Canadian Early Detection of Lung Cancer Study. The first 1,300 participants from the Pan-Canadian study with an estimated 2% or greater lung cancer risk over 5 years (as determined by a risk-prediction model derived from the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial), undergoing LDCT were enrolled. Participants received AF bronchoscopy in addition to LDCT at study entry. AF bronchoscopy was performed by experienced bronchoscopists, and at least one bronchoscopist per center had prior experience with AF. Bronchoscopic quality assurance for image interpretation was conducted in a rigorous manner. LDCT detected 56 prevalent lung cancers (4.3%). AF bronchoscopy led to 776 endobronchial biopsies being performed in 333 of the 1,300 patients (25.6%). AF bronchoscopy identified one carcinoma in situ and four carcinomas. However, the only malignant lesions detected by AF bronchoscopy that were occult on CT were one carcinoma in situ and one carcinoid, so the incremental value of AF bronchoscopy when added to LDCT was 2 of 1,300 or 0.15% (95% CI, 0.0%-0.6%).