The first edition of this valuable handbook was reviewed in this journal by Dr Patricia Weber [Acta Cryst. (1994), D50, 112 ]. This new edition contains revisions of most of the 14 original chapters, sometimes with different co-authors, and adds three new chapters to replace two of those in the original and to expand a third. The chapters dropped are those on automation of crystallization procedures and that on the physical chemistry of protein crystallization. Their replacements include a chapter by S. Veesler and R. Boistelle entitled Diagnostic (sic) of pre-nucleation and nucleation by spectroscopic methods and background on the physics of crystal growth and one by A. Brisson, O. Lambert and W. Bergsma-Schutter on Two-dimensional crystallization of soluble proteins on planar lipid films. The material in the first edition on selenomethionyl proteins has been incorporated in a new chapter by P. F. Berne, S. Doublié and C. W. Carter Jr, entitled Molecular biology for structural biology, which also deals with protein-expression systems and engineering the physical properties of macromolecules.