The local variety of Uyghur spoken in the Atush region has been considered a sub-dialect of the Central dialect together with the Kashgar variety of Uyghur. This paper questions this widely accepted opinion. Based on extensive data collected in Atush during three research trips between 2011 and 2014, it is argued that the vowel system of the Atush dialect is characterized by special features. Although the vowel ä exists, it does not have any distinctive function as in other Uyghur dialects. The paper deals with the vowel inventory of the Atush dialect compared to Standard Uyghur and other Uyghur dialects, and explanations are offered to account for the differences. The role of contact with Kirghiz is discussed.