The synthesis, structural characterization, and NMR studies of new tin(II) alkoxides with thiophene-based substituents are presented. The reaction of ligand HO-C(C4H3S)3(1) with bis(hexamethyldisilazyl)tin {Sn[N(SiMe3)2]2} in the ratio 2:1 in toluene yields the dinuclear compound {Sn[OC(C4H3S)3]2}2∙ 2 toluene (2). The same reaction in tetrahydrofuran allows the isolation of two compounds: a dinuclear {Sn[OC(C4H3S)3]2}2∙ 2 thf (3) and a mononuclear Sn[OC(C4H3S)3]2(thf) (4) molecule. The molecular structures of these tin(II) methoxides containing thienyl substituents2-4were investigated by single-crystal X-ray crystallography. The NMR spectra of solutions of Sn[OC(C4H3S)3]2}2∙ 2 toluene (2) or {Sn[OC(C4H3S)3]2}2∙ 2 thf (3) and {Sn[OC(C4H3S)3]2}2(thf) (4) are almost identical, showing only variations of the molar ratio of the dimeric and monomeric compounds.