This 11th edition celebrates the 61st year of Practical Haematology . The first edition by J.V. Dacie was published in 1950. This work, and subsequent editions with Mitchell Lewis as co-author, were based on the haematology course for the London University Diploma of Clinical Pathology (DCP) and subsequently the MSc in Haematology at the then Royal Postgraduate Medical School. Medical science has expanded exponentially in the last half century, but no discipline has expanded more than haematology, which has often led the way in applying new techniques. This exponential rise is reflected in the parallel increase in the size of this book and in the complexity of the tests described. In this edition we have sought to encompass the full range of tests carried out in a modern haematology laboratory, but recognizing the increasing utilization of commercial ready-to-use kits and point-of-care testing and not neglecting quality control and laboratory organization and management.