Ethnopharmacological Relevance: The only known copy of Sejfer derech ejc ha-chajim, an anonymous old print, is stored in the Austrian National Library in Vienna. It was written in the Yiddish Ashkenazi language and printed in 1613. The author, a Jewish physician, resided or lived in the Polish-Lithuanian Commonwealth. This rare book, although it was printed over 400 years ago, has not yet been systematically assessed in the ethnomedical context of those times., Aim of the Study: A quantitative assessment of the botanical drugs and kinds of healthy diets described in The Guide is presented to recognise the medicinal, diachronic, and botanical outlines of this peculiar rarum., Materials and Methods: To investigate various recipes describing the use of medicinal plants of Jewish culture in the former Polish-Lithuanian Commonwealth, the content of The Guide was analysed. All therapeutic uses of herbal medicines and nutritional recommendations for health were obtained by reviewing the Polish translation of the rare medical handbook. For each plant usage revealed in the text, we noted: Scientific, Common and Yiddish name of the taxon, Plant family, Part of the plant or substance used, Administration, Preparation, Primary pathology, Broad use, and Inferred pathology (ICD-11 and ICPC-3)., Results: Among the 161 recipes, 58 plant taxa and 361 use records were recorded. Additionally, 127 mixtures with 68 plant taxa and 183 use mixture records were noted. 22 diet recipes with 19 plant taxa were also found. These data constitute three separate analyses, according to the intention of the author of The Guide. Formulations using Apiaceae were recommended primarily for gastroenterology and gynecology, while those using Rosaceae for gastroenterology, urology, and neurology. For mixtures, Lamiaceae plants are also represented and used for gastroenterology, respiratory system treatment, and gynecology., Conclusion: The medicinal knowledge described in Sejfer derech ejc ha-chajim fills a gap in contemporary knowledge regarding phyto-medical writing of the Renaissance. The Guide has a form of home first aid kit, used both for medicinal purposes and on the daily menu. In response to current challenges in healthcare, there is a growing interest among researchers in ethnomedicinal sources for the discovery of novel therapeutic compounds. This includes the re-evaluation of formulations and therapeutic indications that have been recognised for centuries. The remedies analysed and detailed in The Guide can provide valuable insights for researchers focused on identifying biologically active therapeutic raw materials of plant origin, thus contributing to advances in modern healthcare., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)