The preparation of 1D WS2 and MoS2 flexible nanoribbons by laser-induced unzipping of the nanotubes is reported. The nanoribbons are of high quality, uniform width, and devoid of surface contamination. The zig-zag edges in WS2 nanoribbons give rise to ferromagnetism at room temperature. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.