Middle English Medical Texts (MEMT) is an electronic corpus including 86 texts and 495,322 words from three traditions of medical writing (surgical treatises, specialized texts, and remedy books) from 1375 to 1500, and an appendix of recipes from c. 1330. MEMT provides a new research resource for several kinds of study. Medical writing shows a great deal of variation even at this early phase, and it is possible to trace linguistic and conceptual developments. MEMT is intended for historical linguists, philologists, and historians of medicine. Most text samples come from edited treatises, but new material (unpublished theses, new transcripts) is also offered. The text samples of the corpus cover 79 codices/manuscripts.The corpus comes with MEMT Presenter, Windows-compatible software to view and browse the texts, and perform text searches. The CD-ROM also contains a JavaScript-based version of the corpus for web browsers in any system, including Macintosh and Linux; this version does, however, not have the advanced corpus search functionality offered by the MEMT Presenter software. In addition, the CD-ROM contains an Introduction by the compilers, background information on texts in the Text Catalogue and Bibliography, and MEMT Presenter Manual.The compilers of MEMT are all researchers at the Research Unit for Variation and Change in English, University of Helsinki. Irma Taavitsainen is Professor of English Philology and Head of the English Department at the University of Helsinki. Päivi Pahta is Fellow of the Helsinki Collegium for Advanced Studies. Martti Mäkinen is preparing his doctorate on Middle English herbals. Their collaborator, Raymond Hickey, is Professor of English Language at Essen University.