In the title compound, C(6)H(6)N(2)O·C(8)H(8)O(3), an equimolar co-crystal of nicotinamide and vanillin, the aromatic ring and the amide fragment of the nicotinamide mol-ecule make a dihedral angle of 32.6 (2)°. The vanillin mol-ecule is almost planar, with an r.m.s. deviation for all non-H atoms of 0.0094 Å. The vaniline and nicotinamide aromatic rings are nearly coplanar, the dihedral angle between them being 3.20 (9)°. In the crystal, the two components are linked through N-H⋯O and O-H⋯N hydrogen bonds into chains along the a axis. The chains are connected via C-H⋯O inter-actions, forming a three-dimensional polymeric structure.