Suspension plasma spraying is a promising modification to traditional plasma spray techniques that may allow plasma sprayed layers with finer microstructures and better porosity control to be produced. The fine microstructures and controlled porosity of these layers, combined with plasma spraying’s ability to produce layers rapidly without requiring a post-deposition heat treatment, makes this an interesting new manufacturing method to produce solid oxide fuel cell (SOFC) active layers. This study uses an axial injection suspension plasma spray system to produce thin, high-density layers of fully stabilized yttria-stabilized zirconia (YSZ) for use as an SOFC electrolyte. Three different aqueous feedstock suspensions with varying solid contents were sprayed, which resulted in coatings with splat thicknesses of approximately 0.5 µm and some intersplat porosity. Total coating thickness increased as the suspension solid content was increased, but suspension flow rates and deposition efficiencies decreased.