The title compound, [Co(II)(C2H8N2)3]Cl2, was obtained unexpectedly as the product of an attempted solvothermal synthesis of cobalt selenide from the elements in the presence of NH4Cl in ethyl-enedi-amine solvent. The three chelate rings of the distorted octa-hedral [Co(C2H8N2)3](2+) complex cation adopt twisted conformations about their C-C bonds. The spread of cis-N-Co-N bond angles [80.17 (6)-98.10 (6)°] in the title compound is considerably greater than the equivalent data for [Co(III)(C2H8N2)3]Cl3 [Takamizawa et al. (2008 ▶). Angew. Chem. Int. Ed. 47, 1689-1692]. In the crystal, the components are linked by numerous N-H⋯Cl hydrogen bonds, generating a three-dimensional network in which the cationic complexes are stacked in columns along [010] and separated by columns of chloride anions.