This research study is primarily an attempt to examine the effects of engaging in strategic planning before retelling narratives with different degrees of storyline complexity on complexity, accuracy, and fluency in the oral production of learners of English as a foreign language (EFL).To this aim, the effects of four task performance conditions (i.e., strategic planning with a single storyline narrative task, no strategic planning with a single storyline narrative task, strategic planning with a dual storyline narrative task, no strategic planning with a dual storyline narrative task) on learners’ complexity, accuracy, and fluency in producing English language were examined. Sixty Iranian intermediate-level EFL learners participated in this study. The results of one-way ANOVAs revealed that though giving learners the opportunity to engage in strategic planning before retelling a narrative with two storylines exponentially advantages complexity, it impairs accuracy. The outcomes have certain theoretical and pedagogical implications for researchers and practitioners in EFL context.