Fluorine,　as　the　most　electronegative　element,　can　replace　the　oxygen　ligands　of　functional　groups　under　given　conditions.　These　fluoride　groups　are　more　or　less　different　from　the　pure　oxide　groups　in　composition,　symmetry,　polarizability,　transmittancy,　etc.　The　rational　use　of　these　differences　is　expected　to　improve　the　probability　of　noncentrosymmetric　structures　and　the　comprehensive　performance　of　second-harmonic-generation　(SHG)　materials.　In　this　feature　article,　we　introduce　the　recent　developments　in　fluoride　selenite　and　tellurite　SHG　materials　together　with　highlighting　our　contributions,　including　Se(iv)　and　Te(iv)　compounds　with　(i)　d0　transition　metal　oxyfluoride　octahedron,　(ii)　IIIA　metal　oxyfluoride　octahedron,　(iii)　fluoride　lone　pair　cation　polyhedron,　and　(iv)　other　fluoride　polyhedron.　The　future　perspectives　of　fluoride　selenite　and　tellurite　SHG　materials　are　also　discussed.　This　journal　is　©　The　Royal　Society　of　Chemistry.