In the title compound, C(15)H(15)NO(4), the quinoline ring system and one of the malonate side chains are essentially coplanar (r.m.s. deviation = 0.0297 Å). The two malonate C-C(=O)-O-CH(3) side chains are oriented at right angles [89.68 (8)°] with respect to each other. The crystal packing is stabilized by weak non-classical inter-molecular C-H⋯O hydrogen bonds, which link the mol-ecules into dimers about inversion centers.