In the title compound, C(10)H(6)F(3)NO(2), the isoindole ring system is planar, the maximum atomic deviation being 0.012 (2) Å. The C-C bond of the trifluoro-ethyl group is twisted with respect to the isoindole ring by a dihedral angle of 62.58 (17)°. Weak inter-molecular C-H⋯O and C-H⋯F hydrogen bonding is present in the crystal structure.