The last decade has seen a rapid expansion in the range and sophistication of diagnostic imaging modalities which are available to clinicians. Our objective has been to produce a manual on paediatric radiology which will prove of value to those clinicians and radiologists in training who are preparing for the Fellowship, Membership and Diploma examinations of various colleges. This teaching manual presents radiographs and examples of other imaging modalities from 100 paediatric patients. The material was taken from a radiological teaching collection obtained from patients at The Hospital for Sick Children, Great Ormond Street, over a lO-year period by one of the authors (C.M.H.). With each case a short clinical history is given and a series of questions posed, similar to those encountered in various postgraduate medical examinations. Sample answers with com- ments and more illustrations are presented on the following page. It has been impossible to achieve comprehensive coverage of the subject in a book of this size, but we have tried to select examples of those cases which illustrate the range of imaging modalities currently available and which may be encountered both in clinical practice and in examinations. We acknowledge with gratitude the kind assistance of Miss Sugarhood in the preparation of the manuscript.