ARTICLE Evidence for one-dimensional chiral edge states in a magnetic Weyl semimetal Co 3 Sn 2 S 2 Sean Howard 1 , Lin Jiao 1 , Zhenyu Wang 1 , Noam Morali 2 , Rajib Batabyal 2 , Pranab Kumar-Nag 2 , Nurit Avraham 2 , Haim Beidenkopf 2 ✉ , Praveen Vir 3 , Enke Liu 3 , Chandra Shekhar 3 , Claudia Felser 3 , Taylor Hughes 4 & Vidya Madhavan 1 ✉ The physical realization of Chern insulators is of fundamental and practical interest, as they are predicted to host the quantum anomalous Hall (QAH) effect and topologically protected chiral edge states which can carry dissipationless current. Current realizations of the QAH state often require complex heterostructures and sub-Kelvin temperatures, making the dis- covery of intrinsic, high temperature QAH systems of significant interest. In this work we show that time-reversal symmetry breaking Weyl semimetals, being essentially stacks of Chern insulators with inter-layer coupling, may provide a new platform for the higher tem- perature realization of robust chiral edge states. We present combined scanning tunneling spectroscopy and theoretical investigations of the magnetic Weyl semimetal, Co 3 Sn 2 S 2 . Using modeling and numerical simulations we find that depending on the strength of the interlayer coupling, chiral edge states can be localized on partially exposed kagome planes on the surfaces of a Weyl semimetal. Correspondingly, our dI/dV maps on the kagome Co 3 Sn terraces show topological states confined to the edges which display linear dispersion. This work provides a new paradigm for realizing chiral edge modes and provides a pathway for the realization of higher temperature QAH effect in magnetic Weyl systems in the two- dimensional limit. https://doi.org/10.1038/s41467-021-24561-3 OPEN 1 Department of Physics and Materials Research Laboratory, University of Illinois Urbana-Champaign, Urbana, IL, USA. 2 Condensed Matter Physics Department, Weizmann Institute of Science, Rehovot, Israel. 3 Max-Planck-Institute for Chemical Physics of Solids, Dresden, Germany. 4 Department of Physics and Institute for Condensed Matter Theory, University of Illinois at, Urbana-Champaign, Urbana, IL, USA. ✉ email: haim.beidenkopf@weizmann.ac.il; vm1@illinois.edu NATURE COMMUNICATIONS | (2021)12:4269 | https://doi.org/10.1038/s41467-021-24561-3 | www.nature.com/naturecommunications 1 1234567890():,;