The recovery of silver from silver-thiosulphate-fixer solutions of radiological wastes has been studied by cementation in batch-stirred reactors using zinc powder as the cementing agent. Silver is efficiently recovered from the solutions. The silver recovery rate and the total silver recovery increased with pH. Metallic silver was the product for cementation in deoxygenated solutions at all pH studied. With non-deoxygenated solutions and at low pH values, metallic silver cemented first, followed by silver sulfide. At high pH values, metallic silver was the cementation product. Electrochemical reactions are proposed for the cementation process in the presence and absence of oxygen.