This research-paper aims at examining the effectiveness of cooperative learning activities in enhancing EFL learners' fluency. The researcher has used the descriptive approach, recorded interviews for testing fluency as tools of data collection and the software program SPSS as a tool for the statistical treatment of data. Research sample consists of (48) first year-students, studying English language in the Faculty of Education at Omdurman Islamic University-Sudan. The students were divided into experimental and control groups for the requirement of the research-paper. The program of the experimental group lasted for a whole month in which much practice was conducted through the Cooperative Learning activities for enhancing the experimental group's fluency. The most important result indicates a statistically significant correlation between the Cooperative Learning activities and the improvement of EFL learners' oral fluency of speaking. The most important recommendation addresses the concerned authorities to train EFL teachers in the use of Cooperative Learning activities in the teaching/learning process for the purpose of furnishing to generalize their use in the various institutions where English language is studied.