Thermal properties and mechanical strength of ceramic fuel-cell components are critical in allowing for rapid start-up and operational stability at high temperatures of solid oxide fuel cell (SOFC) systems. Tubular SOFC electrolytes were prepared using a plastic extrusion technique from a dough containing the electrolyte powders and additives. Strontium- and magnesium-doped lanthanum gallate (LSGM), gadolinium-doped ceria (CGO), and 8 mol % yttria-stabilized zirconia (YSZ) were studied. Burst failure strength, thermal expansion coefficients, and thermal shock resistance of the extruded tubular LSGM, CGO, and YSZ electrolytes were investigated and compared. Three-point bending strength of these three extruded electrolyte materials were tested at room temperature, 600, 800, and 1000°C in air, and the results are discussed. © 2002 The Electrochemical Society. All rights reserved.