Draf III frontal sinusotomy is one of the most complex surgical procedures on the frontal sinus, designed to limit the risks of restenosis by ensuring unification of the two ostia and resection of the floor of the sinus. This procedure requires a good knowledge of anatomy and sufficient surgical expertise to avoid the risk of CSF leak and to limit the risk of restenosis. The surgeon can use various landmarks, consisting of foramina, bone grooves and arteries located on the anterior part of the cribriform plate to guide the procedure. The purpose of this technical note is to explain the use of these landmarks to ensure safe Draf III frontal sinusotomy via a medial approach.