Single crystals of R2Ir2O7 (R = Pr, Eu) have been synthesized using molten KF at 1373 K. The pyrochlore compounds crystallize in a cubic space group Fd(3) over bar m (No. 227, origin choice 2), with Z = 8. At room temperature, the lattice parameters are a = 10.3940(4) angstrom, V = 1122.92(7) angstrom(3) and a = 10.274(3) angstrom, V = 1084.5(6) angstrom(3) for Pr2Ir2O7 and Eu2Ir2O7, respectively. In this paper, we report the crystal growth of R2Ir2O7 (R. = Pr, Eu) and their structure determinations from single crystal X-ray diffraction experiments at temperatures of 110, 115, and 298 K. (c) 2006 Elsevier Ltd. All rights reserved.