Two novel silver iodobismuthates have been obtained: (Et4N)(2n)-[Bi2Ag2I10](n) (1) with one-dimensional infinite chains built from bimetallic tetranuclear units and (Et4N)(2n)[Bi4Ag2I16](n) (2) with a two-dimensional 4(4) grid assembly of the tetranuclear Bi4I16 subunits as nodes and Ag atoms as linkages. Their optical band gaps, 2.05 and 1.93 eV, fit nicely in a size correlation of the Bi/I subunit, which is further supported by the density functional theory studies.