Davidson's 100 Clinical Cases was awarded First Prize in Medicine in the 2009 British Medical Association Medical Book Awards. This book reflects the real world in which doctors practise medicine. The selection of clinical problems guides the reader, step by step, through the correct path in the maze between the presenting complaint of a patient and the final diagnosis. The text emphasises the value of interpreting available clinical and investigative information in a logical way before considering a definitive diagnosis. The 100 cases are based on the 'presenting problems' of Davidson's Principles and Practice of Medicine. The book provides an international outlook reflecting the differences in the practice of medicine in the developing world and in low-resource settings, and addresses the epidemiological, economic and other reasons for many of these important differences. The cases are written by a team of senior doctors, from 12 countries, with considerable teaching experience. The book now includes 100 cases all closely linked to the 'presenting problems' sections of the latest 21st Edition of Davidson's Principles and Practice of Medicine. In this expanded new edition there are many new cases including aluminium phosphide poisoning; occupational lung disease; tremor; and drug interactions.