Abstract New crystalline cobalt, nickel, zinc, and mercury halide adducts with polyethers as ligands have been isolated, characterized, and identified as [Co(μ‐Cl)2CoCl2(glyme)2] (glyme = 1,2‐dimethoxyethane), cis‐[CoI2(H2O)2(glyme)2]2+[CoI4]2–, [NiI2(glyme)2], [ZnI2(glyme)], [HgCl2(glyme)], [CoI2(diglyme)] (diglyme = bis(2‐methoxyethyl)ether), [ZnI2(diglyme)], [HgI2(diglyme)], [CoCl(μ‐Cl)(diglyme)]2, [NiI(μ‐I)(diglyme)]2, [Co(μ‐Cl)(triglyme)]22+[CoCl2(μ‐Cl)]22–, and cis‐[(NiI2)(triglyme)]n. These compounds were obtained from the metal halide salts in solution of glyme or diglyme, and some of them show unusual coordination numbers and arrangements.