Dy(Is2MeTSC)3 [Is2MeTSC= isatin 2-methyl-3-thiosemicarbazone] was synthesized by condensation method. The compounds were structurally characterized by elemental analysis, FT-IR, UV-Vis, TGA and X-ray crystallographic study. The results of the elemental analyses for the compounds were in good agreement with the theoretical values. The X-ray crystallographic structures for Is2MTSC showed that in the solid state, the compound existed in the thione form, where the C=S bond length was shorter than a single bond C-S, which was 1.82 AÌŠ. Is2MTSC adopted an orthorhombic system, a = 14.3434(9), b = 8.4242(5), c = 17.8518(11) AÌŠ and Z = 8. The FT-IR spectral data implied a tri-dentate bonding of Is2MeTSC to Dy(III) ion through carbonyl oxygen, azomethine nitrogen and thiocarbonyl sulfur.