The electrodeposition of NiCu composites using nanometric diameter alumina and ceria was examined using a rotating cylinder electrode (RCE) and a rotating cylinder Hull Cell (RCHC). The RCE polarization behavior was altered by the presence of particles (12.5 g L-1) in the electrolyte. The RCHC was used to survey the composition and deposit thickness, and hence partial current densities in order to determine the cause for the polarization changes. It is the first use of the RCHC to evaluate composite electrodeposition. Cu reduction was inhibited with both alumina and ceria particles, but the nickel and side reaction rates were dependent on the particle type. Alumina particles imparted an enhancement affect on Ni and the side reaction, while ceria did the opposite, resulting in an inhibiting effect. The deposits contained more alumina than ceria, and the alloy composition was altered most with alumina present in the electrolyte compared to a particle-free electrolyte.