The title compound, C(15)H(9)ClN(2)O(2), adopts an E configuration about the C=N double bond. The mean plane of the isoindoline ring system [maximum deviation = 0.011 (2) Å] is inclined to the chloro-benzene ring by 22.62 (8)°. In the crystal, mol-ecules are connected by C-H⋯O hydrogen bonds, forming chains that propagate along [010].