Yeast enolase (2-phospho-D-glycerate hydrolyase, EC 4.2.1.11) has been crystallized by vapor diffusion and equilibrium dialysis of solutions of ammonium sulfate. The crystals with the dimer have 2-fold axial symmetry and appear to be suitable for high-resolution X-ray diffraction analysis. Our potential heavy-atom derivative of the native crystals has been prepared.