This study investigates Chinese immigrant high school students' perceptions of cooperative learning and their interactions during cooperative learning activities in English as a second language (ESL) classes. The findings present a complex picture of cooperative learning in the ESL classroom. The interview results demonstrate that the Chinese students had multiple and contradictory views of cooperative learning. They simultaneously liked and disliked working in groups. The observation data show that these students also produced multiple and conflicting discourses of cooperation, non-cooperation, and mis-cooperation as they worked on cooperative learning tasks. The themes of these contradictory discourses suggest that the Chinese students' everyday lived experiences of cooperative learning in ESL classes were shaped by dilemmatic qualities. The dilemmas these students encountered during cooperative learning tasks seem to derive from conflicting values and practices of the cultural, socio-economic, and educational worlds that these students experienced before and experience now.