The Third Edition of Lecture Notes on Immunology provides a well-balanced coverage of the core knowledge required by medical students. This edition has been completely updated and reorganised to make the subject more accessible to the student, and now is organized into three sections, with six added chapters. Part 1 contains a brief description of immunity, integration of the immune response, and a new chapter on immunological techniques, which are important to the study and diagnosis of disease. Part 2 describes the immunopathology of diseases and contains eight short chapters, including one on HIV and AIDS and another on allergy and transplantation. Part 3 investigates therapeutic aspects of immunology, including immunisation and transplantation, and a new chapter describes the use of immunosuppressives and antibodies. All of the artwork has been redrawn to the highest standards and a colour-plate section is included for the first time. The Third Edition of Lecture Notes on Immunology will appeal to all students who need a working knowledge of immunology but cannot face wading through the ever-expanding alternatives.