Whisker-reinforced ceramic matrix composites comprising a principal crystal phase selected from the group of anorthite, barium-stuffed cordierite, and mixed cordierite/anorthite are prepared by extrusion of extrudable ceramic batches comprising an extrusion vehicle and a solids component consisting essentially of inorganic whiskers and powdered glass, the glass being a thermally crystallizable glass containing an internal nucleant and capable of being consolidated at ambient pressures or above to a dense consolidated preform which may be converted to a substantially glass-free whisker-reinforced ceramic matrix composite by thermal treatment.