The present study investigated the effect of online peer feedback through blogs on Turkish EFL students' writing performance and their perceptions. Data were collected by using: a) Turkish EFL Students' Background Survey, b) interviews at the beginning and end of the term, c) first and revised drafts, and d) end-of-semester Questionnaire. The control group (15 students, classroom-based) attended in-class writing activities and utilized face-to-face oral discussions for peer feedback. The experimental group (15 students, blog-based) attended classes in the computer laboratory and integrated blog peer feedback into their process oriented writing classes. The results of mixed factorial analysis of variances (ANOVA) revealed that the students in both the control and experimental group improved their writing in their revised drafts. However, those in the experimental group showed higher performance in revised drafts. Finally, the analysis of interviews and end-of-semester questionnaires indicated positive perceptions on the use of blogs in their writing classes. (Contains 5 tables and 1 figure.)