The purpose of this study was to examine the effects of cooperative learning (CL) on the academic achievement of student teachers. A mixed-methods sequential explanatory design was implemented in which quantitative data were collected first, followed by qualitative data to clarify the results of the experimental study. Achievement test, interviews, and classroom observations were used for data collection. The results showed that there was a significant difference between the achievement of students in the experimental and control groups in favour of students in the experimental group (p < 0.01). Follow-up interviews and classroom observations indicated that CL creates a suitable learning environment for students, and it strengthens their life skills. Implementing CL in a university classroom provided opportunities for student teachers to learn how to apply CL in their school classrooms. This study was used to firstly, provide insights into student teachers' perceptions of their CL experiences and secondly, to help explain these experiences in more depth.