The aim of this research was to find out the effectiveness of Peer Review for teaching descriptive writing at the first grade of SMK Bakti Purwokerto in Academic Year 2014/2015. This research was conducted by using quasi experimental research. The participants of this research were the first grade students of SMK Bakti Purwokerto. There were two classes : class X AP 2 as the experimental group and class X AP 3 as the control group. In collecting the data, this research used paragraph writing test which was divided into two kinds, there was pre-test and post-test. Based on the computation, t-test result (2.889) was higher than t-table (1.668) with the degree of freedom 68 at the significant level 0.05. In conclusion, Peer Review was effective for teaching descriptive writing at the first grade students of SMK Bakti Purwokerto in the Academic Year 2014/2015.