Cooperative Learning is considered an instructional strategy that encourages students to learn from one another working in groups and pairs. The Aga Khan University, Institute for Educational Development (IED) through its teacher education programmes promotes this strategy in schools particularly in developing countries like Pakistan. The Visiting Teachers Programme (VTP) is one of the examples of IED's attempts to promote cooperative learning. The VTPs are planned, executed and evaluated by the Professional Development Teachers (PDTs) who are graduates of Master of Education (M.Ed) programmes at IED. As a course participant of the M.Ed (2000) programme, I was interested to know about the impact of Cooperative Learning' on two visiting teachers (VTs) who attended the VTP. I decided to conduct an impact study on the above topic. Two VTs of an IED cooperating school of Karachi were selected. Other sample members included, four students (two each) of both the VTs classes. Students were identified for the study with the help of VTs. Head Teacher of the school and the Professional Development Teacher. The study explored ;The impact of cooperative learning on two primary school teachers who attended the primary education Visiting Teacher Programme at IED. This was a case study and literature suggests that for case studies a qualitative research paradigm is more appropriate. Therefore I used the qualitative paradigm and I collected data through interviews, classroom observations, document analysis, field notes and writing memos. Interviews were audio recorded and important points were jotted during interviews. Before entering the field, I went through the programme document which informed me that one of the objectives of the programme was that the VTs understand and practice cooperative learning in their classroom. The programme exposed VTs to alternate teaching methods and instructional strategies. They were taught the basic elements of cooperative learning, lesson planning and teaching, group / pair work and reflections and further were encouraged to use the cooperative learning strategy in the theory practice component of the programme. The study found that teachers have acquired knowledge about cooperative learning. They have tried their best to implement their learning in the classrooms. This includes some elements of cooperative learning in other strategies according to the needs of the students and schools. The findings reveal that teachers have developed good relationships with their students and the students taught by VTs seemed different from other students in terms of social skills. It was also found