One of the most effective treatments of inferior turbinate (IT) hypertrophy is surgical reduction. Bleeding from the IT branch of the posterior lateral nasal artery (ITB) may interfere with the outcome of IT surgery. The aim of this study is to define the anatomic localization of the ITB and its variations and to investigate its clinical importance. Anatomic relations of the ITB were determined by microdissecting 20 adult, sagittally cross-sectioned head specimens. Branching characteristics of the ITB and its anatomical relations were evaluated. The most consistent two markers to define the ITB on the lateral nasal wall were the posterior attachment of the IT (PAIT) and the posterior attachment of the middle turbinate (PAMT). Mean horizontal distances of the ITB from the PAIT and the PAMT were 7.2 mm +/- 2.8 mm (2.5-11.8 mm) and 8.2 mm +/- 2.8 mm (4-14.6 mm), respectively. ITB was the only major artery that supplied the IT in 85% of the specimens, and, in 15%, there was more than one artery. ITB was located lateral to the IT in 95% and medial to the IT in 5%. The ITB coursed on the lateral nasal wall, vertically between the middle and ITs and always anterior to the PAIT. All the variations of blood supply to the IT were within a one square centimeter area, similar to 1-cm anterior to the PAIT. Successful cauterization of this particular area may be an alternative cauterization site in IT surgery. Clin. Anat. 23:770-776, 2010. (C) 2010 Wiley-Liss, Inc.