Cooperative Learning (CL) has been adopted in many countries in recent years. This pilot study looked at a one-year investigation into the teaching of English in Hong Kong secondary school classrooms. The teachers were given support to assist them in designing and carrying out group learning activities. These were organized so that learning was dependent on the socially structured exchange of information between learners in the groups. The data indicated that there were no significant differences in the per formance of the experimental group. However, what did become clear were the difficulties of transferring laboratory-based studies of task performance to the realities of the curriculum-in-action in normal classroom conditions.