2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/79515In this paper, we show that any unknotting tunnel for a two bridge knot is isotopic to either one of known ones. This together with Morimoto-Sakuma's result gives the complete classification of unknotting tunnels for two bridge knots up to isotopies and homeomorphisms.32 pages. Published copy, also available at http://www.maths.warwick.ac.uk/gt/GTMon2/paper14.abs.htmlGeometric Topology57M25, 57M05text