This article focuses on Izniki's translation of Tha'labi's Qisas al-Anbiya' as a valuable gateway to our understanding of features of Old Anatolian Turkish. Comprising of two volumes, the manuscript is incomplete, with a missing second volume. There are two extant copies (Yozgat and Sazeli) of the first volume of the manuscript. An examination of the two copies reveals that both copies contain characteristic morphological and phonetic features of 15th century Old Anatolian Turkish. The manuscript embodies informative information concerning lexical and morphological features of Turkish of the era as well as transitional forms of Turkish. Syntactically, however, the texts carries resemblance to Arabic syntax, attributable to Izniki's profound command of Arabic and Persian and the original language of Tha'labi's work.