The title compound, C(16)H(13)BN(2), is one compound in a series of diaza-borinanes featuring substitution at the 1, 2 and 3 positions in the nitro-gen-boron heterocycle. The title compound is slightly distorted from planarity, with a dihedral angle of 9.0 (5)° between the mean planes of the naphthalene system and the benzene ring. The m-carbon atom of the benzene ring exhibits the greatest deviation of 0.164 (2) Å from the 19-atom mean plane defined by all non-H atoms. The two N-B-C-C torsion angles are 6.0 (3) and 5.6 (3)°. In the crystal, mol-ecules are linked by π-π inter-actions into columns, with a distance of 3.92 (3) Å between the naphthalene ring centroids. Adjacent π-stacked columns, co-linear with the b-axis, are linked by C-H⋯π inter-actions.