High-throughput structural biology is a focus of a number of academic and pharmaceutical laboratories around the world. The use of X-ray crystallography in these efforts is critically dependent on high-throughput protein crystallization. The application of current protocols yields crystal leads for approximately 30% of the input proteins and well-diffracting crystals for a smaller fraction. Increasing the success rate will require a multidisciplinary approach that must invoke techniques from molecular biology, protein biochemistry, biophysics, artificial intelligence, and automation. (C) 2003 Published by Elsevier Science (USA).