Particulate strengthened cobalt-partially stabilized zirconia composites were produced by conventional electro-codeposition method. Tribological properties of the deposits were evaluated against a hardened steel disc under dry sliding conditions on a thrust bearing type disc on disc machine. Dispersion of the particles improved the hardness and tribological properties of cobalt. Load and sliding velocity variations at the interface significantly influence the tribological properties of the deposits. Partially stabilized zirconia showed phase transformations during wear. © 1995.