Presenting a balance between science and clinical relevance, this text is a concise overview of immunology for students. Focusing on what medical students need to know, it aims to be a reader-friendly, patient-oriented text in this challenging field. Experimental detail is kept to a minimum, used only where it helps the student understand difficult concepts. The text has clinical boxes with real patient scenarios, and also provides a review of major components in immunological interaction: important molecules, specific immune response and role of innate response in complementing specific response, and immunity to microbes. Integrating overviews are presented to ensure that the most common failing of immunology teaching - how all the components interact - hoice questions focus the student on the core content which is critical for understanding and progress in the medical curriculum. The text also includes clinical boxes, which place immunology in a clinical context, and technical boxes, which relate immunology to common diagnostic techniques.