The current study aimed at investigating the impact of implementation of reflective audiotaped journals on complexity, accuracy and fluency of second language (L2) speech in a general English for Specific Purposes (ESP) course. To conduct the study, 30 Iranian advanced English as a Foreign Language (EFL) learners of a private language institute in Hamedan, Iran were selected randomly from among 60 learners to participate in the study. In order to put the effect of audiotaped journals on Complexity, Accuracy and Fluency (CAF triad) under close scrutiny, data were collected through audio-recorded initial lectures, videotaped final lectures, reflective audiotaped journals and focus group interview. It is noteworthy to mention that both quantiative and qualitative analyses were conducted to address our research question. Three Wilcoxon Signed Ranks Tests were then employed to compare the second language learners’ oral performance across three measures of CAF, at the beginning and end of the semester. The findings revealed that using reflective audiotaped journals assisted second language (L2) learners to have a better oral performance in terms of complexity (syntactic variety) and accuracy. Furhter, qualitative analysis indicated that using reflective audiotaped journals assisted L2 learners to reflect on their own learning process, resulting in a better oral performance.