We have reproducibly crystallized recombinant trypanothione reductase from Trypanosoma cruzi. Yellow tetragonal crystals in the shape of elongated prisms have unit cell dimensions of a=92.8 Å, c=156.6 Å. Laue symmetry of 4/m and are suitable for a detailed structural analysis. Diffraction data to 2.7 Å resolution have been recorded using synchrotron radiation at the Daresbury laboratory. The structure has been solved by molecular replacement calculations using this synchrotron data and our previously determined Crithidia fasciculata enzyme structure as a search model. The space group has been identified as P43 with a homodimer of approximate molecular mass of 108 kDa in the asymmetric unit. Diffraction beyond 2.5 Å has been recorded when large freshly grown crystals are exposed to X-rays. Refinement of the structure is in progress.