Thin-section CT scans were performed in 40 patients to demonstrate the normal appearance of the lingular division (LD) bronchus and its segmental and subsegmental bronchi and to search out the possible anatomical landmark dividing the anterior segment and LD of the left upper lobe. The LD bronchus was identified in all patients. The complete branching pattern of the lingular segmental and subsegmental bronchi could be traced in 19 (47.5%) patients. Since the lower branch of the draining vein of the anterior segment of the left upper lobe (V3b) runs horizontally between the anterior segment and the LD of the left upper lobe, it is a good landmark dividing the anterior segment and LD of the left upper lobe. Familiarity with thin-section CT anatomy of the lingular segmental and subsegmental bronchi and surrounding vascular structures is helpful in identifying the lingular bronchial tree precisely and localizing a lesion in the left upper lobe correctly.