This study investigates the effect of using rubrics as an instructional tool on students' writing performance in English as a foreign language. The major goal was to liberate the students from the narrow perception of writing based solely on the notion of correct grammar which is strongly felt in EFL writing. In this quasi-experimental research, the treatment group (N = 16) was given a rubric which provided them with a clear set of criteria for good writing. They were guided in using the rubric while writing two different essays. The students in the control group (N = 22) wrote the same essay types but they were not introduced to the rubric. The data were collected through student interviews and their essays, which were evaluated by three independent raters using the same rubric. The results revealed that students who received the rubric outperformed the students in the control group. The analysis of the student interviews proved that integration of the rubrics into the course, though initially somewhat challenging, helped the students appreciate the qualities of good writing and then utilize appropriate strategies to achieve them in their own writing.