The title compound, (C13H10N)2[Co(C6H2N2O4)2(H2O)2]·6H2O, consists of mononuclear trans-[Co(pz-2,3-dc)2(H2O)2]2− complex anions, (acrH)+ cations and uncoordinated water molecules (acr is acridine and pz-2,3-dcH2 is pyrazine-2,3-dicarboxylic acid). The CoII atom, which lies on a crystallographic center of symmetry, has a slightly distorted octahedral coordination environment, with two N and two O atoms from the (pz-2,3-dc)2− ligands in the equatorial plane and with two water molecules in axial positions. In the crystal, the components are held together by two distinct N—H⋯O and C—H⋯O hydrogen bonds with R 2 2(8) graph-sets. The coordinated and uncoordinated water molecules are also involved in O—H⋯O hydrogen bonds, which lead to the formation of layers with R 3 3(12) graph-set motifs. Extensive π–π stacking interactions between parallel aromatic rings of the acridinium ions, with distances ranging from 3.533 (1) to 3.613 (1) Å, occur in the structure.