In this paper, verbs in Western Middle Turkic medical texts have been compared with verbs in Old Uyghur Turkic medical texts. The study aims to explain the valency structures of the verbs of these texts. Verbs in Western Middle Turkic medical texts are mostly the same with verbs in Old Uyghur Turkic medical texts. A lot of the verbs are concerned with obtaining raw materials for drugs and using drugs in treatment. Others are concerned with the causes of illnesses and the results of treatment. In this paper, verbs have been considered on three levels of valency: on the first level, logical valency, mental relations between logical predicates and related elements are analyzed. On the second level, semantic valency, the semantic properties of the arguments are specified by using semantic properties as well as semantic cases. Finally, the third level, syntactic valency, deals with the syntactic properties of arguments, which are at this level called actants or complements.