The purpose of this study was to identify the change (or lack of change) in the classroom practice of science teachers in a government school in Karachi, after completing the eight-week Certificate in Education (CE: Science) programme offered by the AKU-IED. The CE: Science focuses on exposing science teachers to new and innovative methods of teaching in the lower secondary classrooms. It emphasizes the training of teachers within the real classroom, and promotes activity-based science teaching, using low-cost or no-cost materials. I chose to study, in depth, the case of a male teacher, Abdul Sattar, from the Goodwill Government School, Karachi, who had completed his CE: Science last year. The data was gathered through interviews, classroom observations, and post observation meetings. The head teacher's interview, and informal conversations with students, also formed a part of the data. The major findings of the study are those the CE: Science does help change the classroom practice of the teacher, to a small extent. The participant's practice showed that he had perceptibly changed his attitude towards lesson planning, and now engaged in effective planning, where he actively searched for common everyday materials to use in classroom activities in science teaching. He also used demonstration as a method of bringing “alive” science for his students, and engaged in effective questioning, to engage the students. This resulted in enhanced students' motivation and participation in the classroom. Another important result of the CE: Science was that the teacher gave up corporal punishment and started using other means to reprimand, and to motivate students. The teacher also became aware of his need for updating content knowledge and pedagogical skills, and he has, since then, participated enthusiastically in professional development programmes, conducted by the Sindh Government. However, Abdul Sattar faces severe challenges in terms of lack of resources, shortage of teachers, heavy workload and overcrowded classrooms. The lack of parental involvement in school activities, the bureaucratic system and the rigid nature of the school culture are also inhibiting factors for change to occur.