The asymmetric unit of the title compound, [Co(NCS)2(C6H6N2O)3(H2O)]·2.5H2O, comprises one CoII cation, three isonicotinamide ligands, two thio-cyanate anions, one aqua ligand and two water solvent mol-ecules in general positions, as well as one water solvent mol-ecule that is located on a twofold rotation axis. The CoII cations are octa-hedrally coordinated by two terminally N-bonded thio-cyan...