he aim of this paper was to investigate whether planned discussion had equal effect on the parameters of speaking skill namely accent, grammar, vocabulary, fluency and comprehension of Iranian EFL learners at intermediate level at Saee English language institute in Nasimshar, Tehran. 59 students served as the participants in this research. In pre-test the subjects were interviewed on topics that were chosen from interchange series books and all the oral productions were voice-recorded. One rater concerned in each interview to rate them first and after six month they were corrected again by the same rater. After calculating intra-rater reliability of the pre-test, the subjects assigned into two groups of 30 members as control group and 29 members of experimental group randomly. Calculating independent samples t-test showed that the two groups were homogeneous. During 12 session experimental group underwent discussed on the given topics but control group was taught through according to the routine method of teaching. The results of pretest and posttest of both groups were compared. The null hypotheses could be rejected in terms of grammar but it couldn't be rejected in terms of accent,, vocabulary, fluency and comprehension . Although, the difference of the students' posttest attainment probably relates to students' pre-existing differences or the treatment . [ABSTRACT FROM AUTHOR]