The reaction of CuI with 2-(methylthio)thiazole (MTT) in a 1:1 or 2:1 molar ratio (MeCN, rt, 1 h) leads to the coordination polymer [CuI(MTT)]n (CP1) or [(CuI)2(MTT)]n (CP2), respectively. CP1 consists of (–Cu–I–Cu–I–)n zigzag chains wherein the adjacent Cu atoms are bridged by the MTT ligand through the thiazole N and sulfide S atoms. 1-D chains of CP2 are assembled from corner-sharing [CuI3N] and [CuI3S] tetrahedra, which alternate in a zigzag fashion. By contrast, 2-(methylthio)benzothiazole (MTBT) reacts with CuI, regardless of the reactants ratio, to give the dinuclear complex [Cu2I2(MTBT)2], where the planar [Cu(μ2-I)]2 core is supported by the two ligands in the N-monodentate manner. At ambient temperature, CP1 exhibits a weak yellow luminescence (λmax = 570 nm), while CP2 emits in the deep-red region (λmax = 705 nm).