The title compound, C(10)H(10)N(3) (+)·NCS(-)·CH(3)CN, is the acetonitrile solvate of the thio-cyanate salt of protonated dipyridin-2-yl-amine. Protonation occurs at one of the pyridine N atoms. The mol-ecular geometry around the central N atom is essentially planar (sum of angles = 359.89°). In the crystal, N-H⋯N hydrogen bonds, as well as C-H⋯S contacts link the different residues into chains along the c-axis direction. Inter-action between aromatic systems gives rise to π-stacking, the shortest distance between two π-systems being 3.6902 (6) Å. Both the protonated and the non-protonated pyridyl groups are involved in the latter inter-action.