The title complex[Co(nic)2(H2O)4] (nic: nicotinic acid) wassynthesized by hydrothermal methods and characterized by elemental analysis, IR and X-ray single-crystal structuredetermination. The compound crystallizes in the triclinic system, space groupP1with a=14.1363(12) Å, b=6.8778 (5) Å, c=8.4878(6) nm, β=118.297(5)°, V=726.63 (10)Å 3, Dc=1.715 mg·m-3, Z=2, F(000)=386, μ=1.227mm-1, R=0.0191, wR=0.0539[I>2σ(I)], GOF=1.178. X-ray single crystal diffraction analysis showsthe complex is mononuclearzero dimensional structure and the adjacent chains are held together byhydrogen bonds andπ¼πinteractions, forming three-dimensional network. The complex was valued for its antimicrobial activity by diffusiontest in vitro. It was found to be active against the three test bacterial organisms. CCDC: 945007.