There are many primary sources that allow us to reconstruct Old Uighur medicine. This article considers those that demonstrate the following influences: folk medicine, Syriac medicine, Indian and Chinese medicine. The article includes general remarks on the Uighur translations of the Siddhasāra and its role in the history of Uighur medicine: the bilingual version, a list of the preserved parts of the monolingual Uighur version, medicinal plant names, and comments on general translation methods. The Uighur translation deviates considerably from the Sanskrit, but it exploits the medical knowledge it contains in interesting ways. A translation of such a medical compendium like the Siddhasāra was, nor is, an easy task. That we observe equivalents, substitutes and Turkic equivalents in the Uighur version is no wonder. Each of these has to be evaluated carefully. Much scholarly work has already been carried out by H. W. Bailey, R. Emmerick and D. Maue. In particular I would like to mention the contribution of the first editor Reşid Rahmeti (Arat) [Rachmati] who read the texts first and translated them without knowledge of their real source. At that time he had already surmised that the model for the translation must have been a substantial work.