Purpose: To describe the evolution of aspiration risk identification and prophylactic management during general anaesthesia as presented in the United Kingdom (UI 0 anaesthesia textbooks published 1900-t998. Methods: The Cumulated Index Medicus, 1900 -1997, was searched under the headings: anaesthesia, aspiration, and pneumonia for relevant articles. A classification of features was created using key words and phrases: fasting guidelines, gastric emptying, intestinal obstruction and peritonitis, gastro-oesophageal function, upper oesophageal sphincter, raised intra abdominal pressure, pregnancy, posture and difficult tracheal intubation. Finally, 46 20 th century UK anaesthesia text books were studied for the presence or absence of these features. Results: Throughout the century, intestinal obstruction was a recognized risk factor. Only in the 1940s did some authors mention many of the now known risk factors. Hazards for the pregnant patient were described and in the 1960s the importance of the cricopharyngeus muscle was identified. Prophylactic measures included food and water restriction recommendations, especially in the latter half of the century and gastric lavage and drainage were mentioned throughout the century, as was posture at induction. In the 1950s tracheal intubation began to be routinely recommended. In the 1960s, cricoid pressure appeared and then a burgeoning interest in pharmacological control of gastric content character. Awake tracheal intubation is not always mentioned in t 990-96 textbooks. Conclusion: The consensus of information in textbooks since 1970 was lacking in the previous part of the century. Current textbooks are fewer and are published less frequently. Their role in contemporary anaesthesia education and update merits review. Objectif : D&rire, ~ partir des manuels d'anesth&ie publi& au Royaume-Uni de 1900 ~ 1998, I'~volution de ridentification des risques d'aspiration et des mesures prophylactiques pendant une anesth&ie g~n~rale. M~thode : On a examin@ rlndex Medicus cumulatif, 1900-1997, selon les rubriques suivantes 9 anesth&ie, aspiration et pneumonie pour trouver des articles pertinents. On a cr~ une classification des articles selon des mots-cl& et des expressions : ligne de conduite concemant le je0ne, &acuation gastrique, obstruction intestinale et p&itonite, fonction gastro-oesophagienne, sphincter sup~rieur de I'cesophage, ~l&ation de la pression intra-abdominale, grossesse, posture et intubation endotrach~ale difficile. Finalement, 46 manuels d'anesth~sie publi& au 20 e si&le au R-U ont ~t~ examin& pour v&ifler la presence ou rabsence de ces caract&istiques. R&ultats : Tout au long du si&le, I'obstruction intestinale a ~t~ reconnue comme un facteur de risque. C'est dans les ann~es 1940 seulement que certains auteurs mentionnent de nombreux facteurs de risque connus aujourd'hui. Les risques pour les femmes enceintes ont ~t~ d&rits et, darts les ann&s 1960, I'importance du muscle crico-pharyngien a ~t~ identifi&. Les mesures prophylactiques comprenaient, surtout pendant...