Investigations were carried out on 80 right and 80 left lungs removed from human bodies aged 18 to 80 years. The bronchi and pulmonary arteries, after washing, were injected with 65% duracryl and digested with sulfuric acid. On corrosion casts the points of origins, and dimensions of subapical segmental bronchi and arterial branches were investigated. The subapical segment in the right lower lobe was present in 40% of cases. The length of subapical bronchus was 11.5 mm and the diameter 4.1 mm. In 35% the segment was supplied by one artery and in 5% by two arteries. In the left lower lobe the subapical segment was present only in 20% of cases. Its bronchus was 10.6 mm long and 3.8 mm of diameter. Only in 1.25% this segment was supplied by two arteries.