Abstract: An aqueous alkaline plating bath for the electrodeposition of a zinc-nickel alloy coating on a substrate is described. The plating bath generally comprise(A) zinc ions;(B) nickel ions; and(C) at least one heterocyclic compound having the general formulaRN.sup.+ --R.sup.1 --Y.sup.(-)a (X.sup.-).sub.b (I)wherein RN is an aromatic heterocyclic nitrogen-containing group, R.sup.1 is an alkylene or hydroxy alkylene group, Y is --OSO.sub.3, --SO.sub.3, --COOH, --CONH.sub.2 or --OH, X is a halide, a and b=0 or 1, and the sum of a+b=1. Preferably, additional additives are included in the plating bath to improve the properties of the deposited alloy. For example, polymers of aliphatic amines may be included to improve the level of the deposits and metal complexing agents such as hydroxyalkyl-substituted polyamines also may be included. The plating baths of the invention are effective depositing bright alloys over a wide current density range.