In the title compound, C(10)H(2)Cl(4)F(3)NO(2), the isoindoline ring system is almostplanar, the maximum atomic deviation being 0.064 (2) Å. The C-C bond of the ethyl-ene group is twisted with respect to the isoindoline plane by a dihedral angle of 59.58 (12)°. In the crystal, weak inter-molecular C-H⋯F hydrogen bonding links the mol-ecules into supra-molecular chains running along the a axis. A short inter-molecular Cl⋯O contact of 2.950 (3) Å is also observed.