In this paper, RF induction plasma deposition of Yttria Stabilized Zirconia (YSZ) is studied with the objective of producing dense solid electrolyte membranes for Solid Oxide Fuel Cells (SOFC). Different RF induction plasma torch configurations were tested. The results show that high density layers could be obtained using a supersonic Laval nozzle attachment on a standard torch. Coating with apparent porosity of less than 1% could be obtained using this technique at relatively high deposition rates. Optical or electron microscopic examination of the deposit coupled with image analysis show, however, that porosity measurements using these techniques can suffer from relatively large discrepancies depending on equipment setting. A discussion is presented of the validity of this porosity measurement technique.