Abstract: A method of preparing a mixture of zirconia and a stabilising agent for the zirconia comprises milling an aqueous suspension of particulate zirconia and particulate stabilising agent in a bead mill for at least 2 minutes in the presence of a particulate mixing medium having an average particle size from 0.2 mm to 3 mm. Preferred stabilising agents are oxides of yttrium, cerium, calcium or magnesium. Surprisingly, ceramics prepared from the product mixture are more resistant to degradation by attack from water above 100.degree. C. than are ceramics prepared from coprecipitated powders.