This new "FRCEM PRIMARY: All-In-One Notes" provides comprehensive information for understanding the anatomy, physiology, biochemistry, pharmacology, microbiology, haematology, pathology, and evidence-based medicine required for premedical examinations. It remains the leading emergency medicine textbook for candidates preparing for this examination. Given the rapid increase in medical knowledge and time constraints, it is only sometimes possible to read a comprehensive account of all topics or to read individual textbooks independently. Therefore, a method had to be developed to summarise all the information required for the main examination, explain concepts and cover any information that might be questioned concisely and precisely. For these reasons, the introductory book was condensed for the first time in 2015. The original idea was to be a ready source of well-prepared and informative topics that are useful "in practice" and prepare the reader for deeper learning. The colourful format of the book and the use of diagrams make it possible to learn concepts in depth while getting a quick overview of the most important topics that have been asked and are likely to be asked. In addition, the new layout and the numerous additional colourful pictures and illustrations help the candidate to transform abstract information into easily retrievable mental images using the visualisation and association technique and to find information more easily.