Antimony silicates doped with a metal, (M)(x,y)Sb2-xSi2-yO7 (M = W, Ti, Nb), were studied for the removal of the key radionuclides Sr-85, Cs-134, and Co-57 from nuclear waste solutions. Emphasis was given to the removal of radionuclides from acidic effluents for which no efficient commercial exchangers are available. Initial screening tests showed that the undoped antimony silicates (Sb:Si molar ratio similar to 1:1) are highly selective for Sr-85. Distribution coefficients (K-D) of 35,500 mL g(-1) were obtained in 0.1-M HNO3. The antimony silicates also have high or reasonable selectivity for Co-57, Fe-59, and Am-241; but the selectivity for Cs-134 is low. An attempt to increase the selectivity for Cs-134 was conducted by doping the antimony silicate with Ti4+, Nb5+, or W6+. Best results were obtained with a material doped with tungsten, which resulted in an almost ten-fold increase in cesium selectivity in acid. The pyrochlore structure of the materials was also expected to have an effect in creating cesium selectivity. The granular antimony silicate doped with tungsten performed very well in column tests, and high-breakthrough capacities were observed for Sr-85 (> 17,00013V with 1% breakthrough) and Cs-134 (5,000 BV) in 0.1-M HNO3, and for Co-57 (5,200 BV) and Sr-115 (11,000 BV) in neutral simulated pond water. In general, the performance of the metal doped antimony silicates was considerably better than that of commercial materials such as a zeolite, a sodium titanate, and a silicotitanate, which function effectively only in neutral or alkaline conditions and were tested in parallel for reference.