Aninsitumicrowave plasma‐enhanced metalorganic chemical vapor deposition process was used to fabricate highlyc‐axis oriented YBa2Cu3O7−xsuperconducting thin films on metallic Ag substrates. The films were deposited at a reduced substrate temperature of 740 °C in about 270 Pa of N2O ambient. Magnetic susceptibilities versus temperature of the as‐deposited films show attainment of zero resistance of 85 K and composition of single (highTc) phase. X‐ray diffraction measurements reveal that the films deposited at 740 °C have highly preferential orientation of the crystallitecaxes perpendicular to the substrate surface.