In the crystal structure of the polymeric title complex, [Cd(C(11)H(10)O(4))(C(10)H(8)N(2))](n), the Cd(II) cation is chelated by one 2,2-bipyridine ligand and two carboxyl groups from two trimethyl-isophthalate (TMIPA) anions, and is further coordinated by one carboxyl-ate O atom from a third TMIPA anion, forming a distorted penta-gonal-bipyramidal geometry. Each TMIPA anion bridges three Cd(II) cations, forming polymeric complex sheets parallel to (001). Weak C-H⋯O hydrogen bonding occurs between adjacent sheets.