Silver(I) coordination polymers formed by self-assembly of ambidentate ligands, 2-methylisothiazol-3(2H)-one (MI) and 5-chloro-2-methylisothiazol-3(2H)-one (CMI), have been characterized by single crystal X-ray analysis. The structure of the cation in [Ag^I(μ-O-mi)₂]X (X ClO₄⁻ (1); SbF₆⁻ (2)) is a one-dimensional chain while that in the nitrate salt, [Ag^I₂(μ-O-mi)](NO₃)₂ (3), is a three-dimensional network. A silver(I) complex with CMI, [Ag^I(μ-O-cmi)₂]ClO₄ (4), has also been synthesized and the cation has a one-dimensional chain structure. Although both MI and CMI have both O- and S-donor moieties, the oxygen atom dominantly coordinates to the silver(I) centre. The anion influence on the chain structure is attributed to the competition for the coordination ability between anions and MI, and the flexibility of the coordination sphere of d¹⁰silver(I) ion.