Much of our knowledge about molybdenum enzymes has originated from EXAFS spectroscopy. This technique provides excellent bond-length accuracy but has only limited bond-length resolution. We have used EXAFS spectroscopy with an extended data range in an attempt to improve bond-length resolution for the molybdenum enzyme sulfite oxidase. The Mo site of sulfite oxidase has two oxygen and three Mo-S ligands (two from cofactor dithiolene plus a cysteine). For the oxidized (Mo-VI) enzyme, we find that the three Mo-S bond lengths are very similar (within 0.05 angstrom) at 2.41 angstrom, as are the Mo=O ligands at 1.72 angstrom. Density functional theory shows that this is consistent with the proposed active-site structure. The reduced (Mo-IV) enzyme shows two Mo-S bond lengths at 2.35 angstrom and one at 2.41 angstrom (assigned to cofactor dithiolene and cysteine, respectively, from DFT), together with one Mo=O at 1.72 angstrom and one Mo-OH2 at 2.30 angstrom.