The importance of the Genizah for the research of the medieval Mediterranean communities, supplying information on almost every aspect of life, is well known among historian. Less known is that pharmacy was the most popular of all branches of the healing art in the medieval Jewish community of Cairo, according to the Genizah manuscripts. Sources for study of medieval practical drugs are extremely rare since most records naturally vanish over the years, and only some medical books, which contained theoretical pharmacology, have survived to the present day. Drugs lists enable us to understand medieval practical pharmacy and to reconstruct their inventories. This study reports on 71 original drugs lists that were found in the Genizah; they are different from merchants' letters dealing with commerce in drugs and give no instructions for the use or preparation of formulas as usually found in prescriptions. Twenty-six lists are written in Judeo-Arabic and 45 in Arabic, none of the lists is written in Hebrew. The longest list contains 63 identified substances. These lists were apparently used by pharmacists for professional and business purposes as inventories of drugs, records, orders, or even receipts. Two hundred and six different drugs are mentioned in the drugs lists of which 167 are of plant origin, 16 are of animal origin, and the remaining 23 are inorganic. The lists point directly to the place they occupied on the shelves of the pharmacies that could be found in the lanes and alleys of the Jewish quarter of Cairo. The most frequently mentioned substance were myrobalan (27), pepper and saffron (21), lentisk (15), almond, basil, rose, rosemary (14), cattle products, camphor and spikenard (13).