I’ll explain the construction of generalized motivic cohomology groups, in the spirit of Voevodsky usual motivic cohomology groups, but with Chow-Witt groups replacing Chow groups in the machinery. I’ll try to explain why these groups are interesting, and give some ideas about the proof of a theorem identifying the diagonal part of these generalized motivic cohomology groups of a field with Milnor-Witt K-theory of that field. (joint work with Jean Fasel)