The Medical Formulary of Al-­Samarqandi demonstrates the high development of pharmacology by the Arabs in the Middle Ages. It was far from a dark period in science for it was in this area, as well as in Arabic optics and chemistry, that experimental science first began to develop. This is shown by al-Samarqandi's work which describes many new drugs, chemical processes, and a more advanced pharmacological theory. No part of this work has ever before been brought to the notice of historians of medicine. For the first time, the authors give a complete translation of this AqrÂbōdhīn in order to present a complete picture of the pharmacological knowledge of the day.There is a comprehensive section of Notes and Comments with particular attention being drawn to the present-day usage of old Arabic drugs, the employment of the drugs in the much earlier al-Kindi Medical Formulary, and to the etymological discussion of Arabic plant names not studied in previous works on the subject. Finally there is a Glossary of Arabic-English terms and a selected Bibliography.