Crystallization of the title compound, di-mu-pyridazine-1 kappa N-2:-2 kappa N-2'-bis[(2,3-dihydro-3-oxobenzisosulfonazolato-kappa N)silver(l)], [Ag-2(C7H4NO3S)(2)(C4H4N2)(2)], from acetonitrile yields both monoclinic, (1), and triclinic, (11), polymorphs. In both forms, the silver(l) ions have a slightly distorted trigonal AgN3 coordination geometry and are doubly bridged by two neutral pyridazine (pydz) ligands, generating a centrosymmetric dimeric structure. The saccharinate (sac) ligands are N-coordinated. The dihedral angles between the sac and pydz rings are 8.43 (7) and 7.94 (8)degrees in (1) and (11), respectively, suggesting that the dimeric molecule is nearly flat. The bond geometry is similar in both polymorphs. In (1), the dimers interact with each other via aromatic pi(sac)-pi(pydz), stacking interactions, forming two-dimensional layers, which are further crosslinked by weak C-H center dot center dot center dot O interactions. Compound (11) exhibits similar C-H center dot center dot center dot O and pi-pi interactions, but additional C-H center dot center dot center dot pi and pi center dot center dot center dot Ag interactions help to stabilize the packing of the dimers.