The paper reports results of research on the effects of streaming on boys and girls in secondary schools in Jamaica. The study found that girls were more represented in high stream classes, while boys were more represented in low stream classes. Streaming affected academic achievement, students' experiences of school practices such as being beaten or insulted, and students' sense of alienation from school. There were gender differences in all responses, with low stream boys most likely to do poorly academically and to experience negative school practices. However, low stream girls were the group most likely to feel alienated from school. Implications of these results for equal educational opportunity and equal access to knowledge are discussed.