The aims of this study were to examine changes in students' English and math self-concepts and to investigate the effects of gender and school ability level on these changes. Self-concept in English and math were measured thrice across three years among a sample of 2618 secondary school students from Hong Kong. Gender and school ability level were included as time-invariant predictors. Results indicated that students' English self-concept slightly increased across time, while math self-concept marginally declined. Gender influenced both the initial levels and rates of change for English and math self-concepts, while school ability level predicted initial levels of self-concept. Implications are discussed.