The anomalous electrodeposition of NiCoFe ternary alloys was examined. Ni deposition in the ternary system appeared inhibited compared with its single-metal deposition, which characterizes typical anomalous behavior. Fe deposition was enhanced, similar to recent findings in codeposited binary alloys. Both catalytic and inhibiting effects were observed for Co deposition. The inverse Tafel slopes for both the metal reduction reactions and the side reactions were determined and compared with the values obtained during the single-metal reductions. A common change in the inverse Tafel slopes suggested a dependent kinetic relationship between the metal and side reaction rate during NiCoFe alloy deposition.