In the title herbicideh/phytocide, known as imaza-pic, C(14)H(17)N(3)O(3), the pyridine and imidazole rings are almost coplanar [dihedral angle = 3.08 (5)°]. An intra-molecular O-H⋯N hydrogen bond occurs. In the crystal, an N-H⋯O hydrogen bond links mol-ecules into a chain parallel to [010].