This study was primarily aimed at investigating the effects of simultaneous use of reasoning demand (resource-directing) and prior knowledge (resource-dispersing) on fluency, accuracy, and complexity of L2 oral performance. More, specifically, an attempt was made to investigate how EFL oral production could be affected by ±reasoning demand and ±prior knowledge in the local context of Iran. Thirty male and female Iranian intermediate EFL learners whose mother tongue was Persian and whose age ranged between 23 and 29 were chosen as the participants in this study, and a pretest-posttest quasi-experimental design was utilized. Assigned to two experimental conditions, participants were engaged in a narrative task in which two different wordless picture stories were chosen for data collection. Such statistical operations as t tests and MANOVA were applied to analyze the data. The results obtained from t tests revealed that in ±reasoning demand condition, both complexity and accuracy significantly improved whereas the results for fluency were not statistically significant. In addition, with regard to the ±prior knowledge group, similar results were obtained. In the end, conducting MANOVA revealed that both groups were not different in the pretest; however, utilizing the same procedure for the posttest illustrated a difference between the two groups in terms of their accuracy and complexity, but not their fluency. The results bear some implications for L2 oral production and practice as controlled by teachers and practitioners in EFL contexts.