The aim of this study was to investigate the effect of using TED talks-based instruction in developing EFL speaking fluency among secondary stage students. The design of the study is one group, pre and posttest. The participant of the study consisted of second year secondary stage students at Integrated Distinct Governmental Language Secondary School in Shebin Elkom (N=30). The instruments and material used included: an EFL speaking fluency checklist required for second year secondary stage students, two EFL speaking tests (used as a pre and a posttest) and an analytic rubric for scoring them and a teacher's guide for using TED talks-based instruction. The EFL speaking pretest was administered to the participants. The participants were taught using TED talks-based instruction to develop their EFL speaking fluency. Then, the posttest was administrated again. t-test was used to compare the mean scores of the pretest and the posttest of the study participants. Results of the study revealed that there are statistically significant differences between the mean scores of the study participants in the pre and post assessment of EFL speaking fluency in favor of the post assessment, so the EFL speaking fluency of the participants was developed as a result of using TED talks-based instruction. Therefore, it can be concluded that using TED talks-based instruction was effective in developing EFL second year secondary stage students' speaking fluency.