We are delighted to introduce the 9th edition of Dacie and Lewis's Practical Haematology. This highly successful, practical manual continues to describe all of the techniques used in the investigation of patients with blood diseases. It discusses the principles of each test, possible causes of error, and the interpretation and clinical significance of the results. The use of standards, reference reagents and quality control is stressed throughout and new information and techniques have been added to bring this edition right up-to-date.