Fine-particle (Sr,Na)ZrO3 was prepared by boiling a suspension of zirconium and strontium hydroxides in concentrated NaOH and was characterized by powder x-ray diffraction, thermogravimetry, IR spectroscopy, scanning electron microscopy, and x-ray microanalysis. Its structure was refined by the Rietveld method. (Sr,Na)ZrO3 has an orthorhombically distorted perovskite (ABO(3)) structure, with the Sr2+ and Na+ ions in the A site and Zr4+ in the B site. The relative A- and B-site occupancies are 100 and 79%, respectively. The cation deficiency is compensated by OH groups, which contain about one-third of the oxygens. In the range 100-900degreesC, (Sr,Na)ZrO3 loses water but retains the perovskite structure (with reduced lattice parameters). The synthesized powder consists of similar or equal to40-nm particles, which form micron-sized spherical aggregates. The aggregates retain their shape during annealing at temperatures of up to 1000degreesC.