A new Co(II) complex with 2,6-diacetylpyridineisonicotinoylhydrazone has been obtained and analyzed by elemental analysis, IR and X-ray study. Crystals suitable for X-ray difraction were obtained from the mixture of Co(SCN)2 – 2,6-diacetylpyridine – isoniazid in 1:1:2 molar ratio which was stirred in the presence of pyrazinecarboxamide for about 3 h. As result the NO₃ anion has found in the crystal which has formed from reactants, most probably from oxidation of NCS anion. In the IR spectrum has found the bands ν(CH3) 2932, 2884 cm-1 and δ(CH3) 1466 and 1375 cm-1 attributed to 2,6-diacetylpyridine; ν(NH) 3230 and ν(C=O) 1638 cm-1 for isoniazid; 2095 and 1300 cm-1 which are characteristic for NCS and NO3 anions respectively. The X-ray crystal structure has demonstrate that the new compound has the formula [Co(H4L)(NCS)2](NO3)2·2H2O, where H4L2+ acts as positive bicharged 2,6-diacetylpyridineisonicotinoylhydrazone ligand (Fig. 1). The seven-coordinated Co(II) ion has a pentagonalbipyramidal environment. The planar pentadentate bis-Schiff base ligands coordinate in basal plan through N3O2 donor atom set. As result of coordination organic ligands to Co(II), four adjacent pentadentate ring are formed, the dihedral angles between planes of these rings being in the range 3.05 – 7.74º. The apical positions of pentagonal-bipyramidal polyhedra are occupied by nitrogen atoms of two NCS- anions. In the external sphere  NO₃ anions and crystallization water molecules are found. Due to of four negative charges (two NCS- and two NO₃ anions) in the molecule we supposed that the nitrogen pyridine of isoniazid is protonated. This fact was confirmed in two ways: a) the presence of the absorption at 2420, 2297 and 1877 cm-1 region in the IR spectrum and b) CNC angle of pyridine ring of isoniazid is 121.33º. In the crystal the complex cations [Co(H4L1)(NCS)2]2+ are linked with some of  NO₃ anions directly through N–H···O hydrogen bonds, being formed chains which are stabilized through С(4)–Н···O(2N) (C···O 2.960 Å, H···O 2.28 Å, angle CHO 129^o). A 3D supramolecular network are formed due to H-bonds system. Here the cristalization water molecules participate both as donor and acceptor protons which link the complex cations O(W)– H···S, N–H··· O(W), and С(5)–Н···O(1W) (C···O 3.193 Å, H···O 2.57 Å, angle CHO 124^o) directly and trhough  NO₃ anions O(W)–H···O(N) and С(2)–Н···O(3N) (C···O 3.286 Å, H···O 2.38 Å, angle CHO 165^o) indirectly.