The title complex, [Co(C(15)H(11)N(3))(2)](C(4)N(3))(2), is built up from discrete [Co(terpy)(2)](2+) cations (terpy is 2,2':6',2''-terpyridine) and [C(CN)(3)](-) anions. In the cation, the Co(II) atom is coordinated by two terpy mol-ecules, giving a distorted octa-hedral geometry. The tricyano-methanide anions are not directly coordinated to the Co(II) atom, but some weak C-H⋯N hydrogen bonds involving the terminal N atoms of the tricyaomethanide ions and the terpyridine H atoms link anions and cations building a three-dimensional network.