Around the year 1000, Muslim physician Abu al-Qasim Khalaf ibn al-?Abbas al-Zahrawi composed a voluminous medical encyclopedia, Al-Tasrif li-man ?ajiza ?an al-taMODIFIER LETTER RIGHT HALF RINGlif, the thirtieth treatise (Al-Maqala al-thalathun) of which was subsequently translated into many languages, for embodying a ground-breaking illustrated work on the surgical knowledge and instruments of its time. In Anatolia circa 1465, the Ottoman physician Serefeddin Sabuncuoglu produced his own surgical magnum opus Cerrahiyyetu'l-haniyye by rendering this work into Turkish and replicating its instrumental drawings, and adding to it new chapters and supplementary miniatures. In this study, we both confirm the genuineness of the added chapters by comparison with Leclerc's French translation of Al-Maqala al-thalathun, which similarly appears to contain additional parts, and investigate the nature of the core text annexed from Al-Maqala al-thalathun. In producing the translated portion of his work, Sabuncuoglu remained for the most part within the bounds of metaphrasis, i.e., literal translation, though with both significant and insignificant instances of paraphrasis based on omission or interpolation. The relatively insignificant instances typical of most medieval works of translation include contributions of adjectival, adverbial or nominal specification, further elaboration and non-essential addition in one or a few words. The longer instances include professional anecdotes interpolated occasionally either with some demarcating verba dicendi or through a seamless transition, and missing lines that appear to have been omitted or to be absent due to their unavailability in the source text(s). By presenting a number of typically exemplifying excerpts, we attempted to specify these divergences of Cerrahiyyetu'l-haniyye from Al-Maqala al-thalathun, to which the literature so far has very generally referred as "the contribution of Sabuncuoglu". Moreover, we found that the second set of paraphrastic divergences, to which we attributed special significance, provided clues as to the source text(s) of Cerrahiyyetu'l-haniyye, by which we propose a connection with the contemporaneous Huntington manuscript.