Advanced concepts for large, furlable space antennas have led to an extensive development program at the Jet Propulsion Laboratory (JPL) with configurations utilizing conical main reflectors. The antenna subreflectors for these conical configurations have unusual geometries and new structural requirements. Structural efficiency of the conical antennas is improved through the use of fiber composites and, as part of JPL's development program, a subreflector was designed and fabricated with graphite/epoxy material. This was sized to fit a subscale, 6-ft-diameter model. The subreflector is a cylindrical paraboloid with demanding criteria for contour surface precision, high thermal stability, and sufficient structural capacity for inertial launch loads in axial and transverse directions (12 to 18 g). In addition, dynamic launch environments impose constraints on allowable natural frequencies. This application presents broad design requirements and novel fabrication constraints. The paper describes the design, analysis, and fabrication of the subreflector.