Immunology – the study of the way in which the body defends itself – has developed rapidly. It is a speedily moving field that is contributing critical tools for research and diagnosis, and therapeutics for treatment of a wide range of human diseases. Studying Immunology has always been a burden for most students. It has become a priority to understand the molecular and cellular basis of the immune system for rheumatic diseases in anticipation that it will facilitate more accurate diagnosis and inform therapeutic decision making. It seems vital to show the depth of the twinning between Rheumatology and Immunology, which are two sides for the same coin. Rheůmmunology is designed to provide simple, basic and advanced knowledge of immunology of relevance to the pathogenic pathways that underpin autoimmune rheumatic disease. It is unique in displaying knowledge in a simplified, easy-to understand way that starts from the ABCDEs of the immune system, Basic and Complex rheůmmunology passing to Disease-specific and Experimental Rheůmmunology. Illustrations are made in an easy way to confirm the information provided in the text. It is difficult to think of a more exciting area of medicine.