For years, active instructional methods have been growing rapidly in second/foreign language educational context. Despite the effort of scholars, teachers still have major difficulties in the implementation of such methods in their classes (Todhunter, 2007). Instructional conversation (IC), proposed by Tharp and Gallimore (1988), is a type of active instructional methods which are based on group discussion and has the potentiality of developing learners' second/foreign language skills. Therefore, the present study sought to examine the impact of IC on Iranian EFL learners’ speaking skill, WTC, and attitude towards English learning. To this end, a number of 80 homogenized female EFL learners were randomly assigned to four groups including group 1: experimental lower intermediate learners, group 2: experimental upper intermediate learners, group 3: control lower intermediate learners, and group 4: control upper intermediate learners; each group consisting of 20 EFL learners. Then, the subjects were asked to complete two validated Persian versions questionnaires including Willingness to Communicate in a Foreign Language Scale (Baghaei, 2012) and Attitude towards English Learning Questionnaire (Soleimani & Hanafi, 2013) at both pre and posttest phases. Moreover, to evaluate speaking skill, the subjects of four groups sat IELTS Speaking Tests before and after receiving the treatment. During 14 treatment sessions, ICs were conducted in groups 1 and 2 based on Goldenberg and Gallimore's (1991) model while the control groups, i.e., 3 and 4 received no instruction. Based on the results of two-way ANOVAs, IC had significant impacts on EFL learners' speaking skill and WTC development; however, it had no significant effect on EFL learner' attitude towards English learning. Moreover, regarding the difference among the effects of IC on the performances of four groups in speaking skill, WTC, and attitude towards English learning, the results of MANOVA showed that IC had a statisti
