A manganese-zirconium mixed hydrous oxide with Mn to Zr mole ratio of 1:1 was prepared to study the sorption behavior and the removal of strontium from acidic radioactive waste solutions. Mixed hydrous oxide was identified and characterized by DTA/TGA, XRD, and surface analysis. The parameters affecting strontium adsorption, such as initial pH, contact time, initial metal ion concentration, temperature, adsorbent dose, and selectivity towards competing ions were investigated. Sorption data have been interpreted in terms of Freundlich and Langmuir equations. Thermodynamic parameters such as standard enthalpy (Delta H degrees), entropy (Delta S degrees), and free energy (Delta G degrees) were calculated from the slope and intercept of the plots of ln K-D versus 1/T. The results indicated that the sorption of strontium onto manganese-zirconium mixed oxide is endothermic and spontaneous in nature.