X-ray powder diffraction data for In3.85Zr2.80Sn0.35O12 are reported. The powders were prepared using a wet-chemical precipitation method. The XRD data could be fitted with a rhombohedral unit cell in space group R3 (No. 148). The Rietveld refined unit cell parameters are a=0.951 49(2) nm and c=0.889 51(2)nm in a hexagonal setting with Z=3 and Dx=6.69(1)g/cm3.