The aim of this study determines the effect of written peer assessment on Turkish students' writing anxiety as a foreign language. One pattern of the working group's research subjects used in Turkey Religious Foundation in Ankara contains 24 students who learn Turkish as a foreign çmlanguage C1. In the study, while peer assessment was conducted for six weeks, the students wrote compositions on different subjects and these compositions were evaluated by their peers in line with the information contained in the peer assessment form. In order to measure students' writing anxiety before and after the application, the writing anxiety scale, which was previously experienced for validity and reliability, was used. The obtained data were analyzed with percentage frequency and t-test in dependent sample. As a result of the study, a significant relationship was found between peer assessment and written expression anxiety levels of students in C1 level who learn Turkish as a foreign language. Accordingly, it was found that anxiety levels in the pre-test of the participants' written expression skills decreased in the post-test.