This is the first comprehensive account of diffuse neutron scattering, a unique tool for determining structural disorder in solids. The text takes the reader through theoretical, computational and experimental developments in the subject and describes in detail its application to a number of structural disorder problems. These include the more traditional subjects of substitutional disorder in alloys and orientational disorder in molecular systems as well as the more recent studies of superior and framework materials. Particular emphasis is placed on recent refinement methods for data interpretation and these are compared with established computer simulation techniques and analytical approaches. The book collects disparate themes into one unique volume, which is written as an introduction to the methods for graduate scientist and as a valuable reference or the expert crystallographer who wishes to apply modern interpretative techniques to diffuse scattering data.