In the title compound, [Co(N3)2(H2O)4]·C14H12N2O4·2H2O, the metal complex molecule is centrosymmetric, the Co(II) ion being six-coordinated by two azide N atoms and four aqua O atoms with a trans-octahedral geometry. The zwitterionic organic molecule is also centrosymmetric. In the crystal, the components are associated into a two-dimensional network through O—H⋯O hydrogen bonds. Further O—H⋯O and O—H⋯N interactions give a three-dimensional structure. The free water molecule is disordered over two positions in a 0.787 (5):0.213 (5) ratio.