The British Society for Immunology is one of the oldest, largest, and most active, Immunology societies in the world and is the largest in Europe. Its members are based all over the world, with the majority working in Britain. The BSI was founded in 1956 by a small group of hard working, visionary immunologists, who wanted to come together to share ideas.

Members of the Society work throughout the entire Immunology chain, stretching from the laboratory bench right through to the clinics and hospitals in which patients are treated - from discovery to delivery. The fields in which they work are wide and extensive, from HIV/AIDS to allergy, diabetes, malaria, TB, animal health, arthritis, transplantation, vaccination and infectious disease.

The BSI's flagship event is its Annual Congress, the largest national Immunology congress in Europe, with over 1500 attendees. The Congress has been going since 1993. Attendees are drawn from all sectors of the immunological community, from researchers to clinical immunologists. The BSI has long been committed to providing access to these, and additional meetings, and to developing programmes in research, public engagement and education. The BSI also supports a network of regional groups which run programmes of lectures, seminars and residential meetings. The Society provides grants and bursaries to enable immunologists to attend important meetings and to interact with their peers and to discuss their work with eminent international speakers.