The present research aimed at investigating the effect of using collaborative online discussion strategy on enhancing secondary stage students' EFL oral fluency. The research followed the quasi experimental design of two groups (control and experimental). A total of forty EFL first year secondary stage students of Hurghada secondary official language school, Red Sea governorate, Egypt, were randomly assigned to two groups; twenty students for the control group and twenty for the experimental. The researcher designed and used the instruments and materials of the research, which included: an EFL oral fluency skills list, an EFL oral fluency test, an EFL oral fluency scoring rubric, and an instructional unit based on collaborative online discussion strategy. The results of the research showed the statistically significant differences between the mean scores which obtained by the experimental group in the pre/posttest of the EFL oral fluency (in favor of the posttest). Moreover, there were statistically significant differences between the mean scores of the experimental and the control groups in the post test of the EFL oral fluency (in favor of the experimental group). Therefore, the impact of using collaborative online discussion strategy on enhancing secondary stage students' EFL oral fluency has been verified