The title compound, (C(16)H(36)N)(2)[Cd(C(5)O(3)S(2))(2)]·0.25H(2)O, contains two disordered tetra-butyl-ammonium cations, a complex [Cd(C(5)O(3)S(2))(2)](2-) anion and a 0.25-hydrate water. The anion is composed of a bidentate coordinated 3,4,5-trioxocyclo-pent-1-ene-1,2-dithiol-ate (dtcroc) group forming a distorted tetra-hedral configuration around the Cd(II) ion. The dihedral angle between the least-squares planes of the ten-atom sulfur-substituted croconate groups in the anion is 84.10 (8)°. The crystal packing is stabilized by weak C-H⋯O and C-H⋯S cation-anion hydrogen-bond inter-actions. In each of the two cations one butyl group is disordered over two positions in the ratios 0.589 (11):0.411 (11) and 0.796 (12):0.204 (12).