In the title compound, [Co(C 8 H 6 N 3 O 2 )Cl(C 2 H 5 OH)] n , the Co II atoms adopt octa-hedral trans -CoN 2 O 4 and tetra-hedral CoCl 2 O 2 coordination geometries (site symmetries and m , respectively). The bridging μ 3 - O : O : N 2-(benzotriazol-1-yl)acetato ligands connect the octa-hedral cobalt nodes into (010) sheets and the CoCl 2 fragments link the sheets into a tri-periodic network. The structure displays O-H⋯O hydrogen bonding and the ethanol mol-ecule is disordered over two orientations.