We carried out single crystal X-ray diffraction measurement of tetragonal form PbSnF4 : a = 4.215(3) angstrom, c = 11.744(32) angstrom, V = 208.6(5) angstrom3, spacegroup P4/nmm, z = 2, and D(calc) = 6.26 g/cm3. The structure was refined to wR = 0.031 by the least-squares methods, using 132 reflections. The compound has the order arrangement of Pb and Sn metals constructing the sequence of ...PbPbSnSnPbPb... along the c-axis direction. The fluorine ions in M2(Sn) cube were disordered in distorted tetrahedra. It is considerable that the disordered ions are related with the high ionic conductivity in PbSnF4.