AbstractThe title compound, C13H2F10N2O, has been previously described in the space group Pbca with Z = 8 [Jai-nhuknan et al. (1997 ▶). Acta Cryst. C53, 455–457]. The current P212121 polymorph was obtained from a tetrahydrofuran solution. The pentafluorophenyl rings make dihedral angles of 50.35 (6) and 54.94 (6)° with the urea fragment, in close accord with those reported for the first polymorph. In the crystal, both of the N—H groups donate H atoms to the same carbonyl O atom, forming a one-dimensional molecular array along the a axis. There are close contacts between perfluorophenyl C atoms within the array [3.228 (3) Å] and halogen bonds are also observed between the arrays [F⋯F = 2.709 (2) and 2.7323 (18) Å].