In the title compound, C(8)H(8)N(4)·C(8)H(8)N(4), two tautomers, viz. 3-phenyl-1,2,4-triazol-5-amine and 5-phenyl-1,2,4-triazol-3-amine, are crystallized together in equal amounts. The 3-phenyl-1,2,4-triazol-5-amine mol-ecule is essentially planar; the phenyl ring makes a dihedral angle of 2.3 (2)° with the mean plane of the 1,2,4-triazole ring. In the 5-phenyl-1,2,4-triazol-3-amine tautomer, the mean planes of the phenyl and 1,2,4-triazole rings form a dihedral angle of 30.8 (2)°. The π-electron delocalization of the amino group with the 1,2,4-triazole nucleus in the 3-phenyl-1,2,4-triazol-5-amine mol-ecule is more extensive than that in the 5-phenyl-1,2,4-triazol-3-amine tautomer. The mol-ecules are linked into a two-dimensional network parallel to (100) by N-H⋯N hydrogen bonds.