The aim of this paper is to illustrate how language laboratory affects language writing skill of Iranian English learner. To do so, a group of 13 first year English language students (ELS) was randomly assigned as sample. The participants were trained via a formal university program for 30 sessions in one semester. The study was quasi-experimental with pretest and posttest and without control group. The results of analyzing via paired t-test indicated that there were significant differences between the scores of pretest and posttest assessments (P<0.05).
