A method of toughening a fiber/matrix ceramic composite consisting of non-oxide based ceramic fibers immersed in a ceramic matrix. The method includes, prior to immersing the fibers in the matrix, applying a metallo-organic solution of a noble metal to the fibers to form a coating of the solution on the fibers, evaporating the solvent from the solution and oxidizing the residual organic compounds whereby the coating becomes a pure noble metal and immersing the coated fibers in the matrix. The applying, evaporating, oxidizing and immersing steps are characterized by a limited raising of the temperature of the fibers. The coating is ductile so as to blunt advancing cracks in the matrix.