The title compound, C(11)H(13)N(3)O, is a derivative of the anti-tuberculosis drug isoniazid [systematic name: pyridine-4-carbohydrazide]. The crystal structure consists of repeating hydrogen-bonded chains parallel to the b axis. Adjacent mol-ecules in the chains are linked by bifurcated N-H⋯(O,N) hydrogen bonds, which form an R(1) (2)(5) ring motif.