This study reports on a high school teacher using emancipatory action research to implement cooperative learning strategies in a chemistry class. Data were collected and analyzed using qualitative methods. The findings of the study indicate: (1) students accept cooperative learning if they feel it can increase their ability to learn content; (2) students need to be responsible for their own learning in order to benefit from cooperative learning; (3) cooperative learning increases reflective thinking ability, content learning, and social skills in students; and (4) testing culture and time constraints influence teacher implementation of cooperative learning. (DDR)