N-(4-Isocyano-phen-yl)succinamic acid.

In the crystal structure of the title compound, C(11)H(10)N(2)O(3), inversion-related mol-ecules are connected by pairs of O-H⋯O hydrogen bonds. With the exception of the atoms in the carb-oxy-lic acid group, the non-H atoms are roughly coplanar with a maximum deviation from the mean plane of 0.270 (1) Å for the C atom to which the carb-oxy-lic group is attached.