The compound (Z)-2-N'-hydroxyisonicotinamidine, (2) was synthesized and characterized by H-1 NMR, FT-IR, FAB-Mass, UV-Visible Spectra, and elemental Analysis. Its molecular structure was solved by single crystal X-ray diffraction method. The title molecule, C6H7N3O is crystallized in the orthorhombic crystal system with the space group Pna2(1) and with unit cell parameters a = 12.5664(8) angstrom, b = 8.8622(6) angstrom, c = 5.7953(4) angstrom, alpha = 90 degrees, beta = 90 degrees, gamma = 90 degrees, and Z = 4. The molecular and crystal structure of the title molecule is stabilized by an intramolecular interaction of the type N-H center dot center dot center dot O, and the intermolecular interactions of types N-H center dot center dot center dot N and O-H center dot center dot center dot N.