A tungsten alloy electroplating bath. Highly ductile tungsten alloy deposits are facilitated using a sulfur co-depositing ductility additive such as: ##STR1## wherein R.sub.1 is selected from the group consisting of H.sub.1, alkyl, alkenyl, hydroxy, halogen, carboxy and carbonyl;"AR" designates a benzene or naphthalene moiety;R.sub.2 is selected from the group consisting of H, or an alkyl sulfonic acid, a Group I or Group II salt of an alkyl sulfonic acid, a benzene, a sulfonate, a naphthalene sulfonate, a benzene sulfonamide, a naphthalene sulfonamide, an ethylene alkoxy, a propylene alkoxy; and R.sub.2 may be attached to "AR" to form a cyclic moiety; andR.sub.3 is selected from the group consisting of a benzene, a naphthalene, an unsaturated aliphatic group; and a benzenesulfonate group.The additive provides ductility improvements in tungsten alloy electroplates deposited from the solution.