This study investigated how gender shapes the relationships between classroom environment, achievement goals and maths performance. Seventh-grade students ("N"?=?498) from five urban secondary schools filled in achievement goal orientations and classroom environment scales at the beginning of the second semester. Maths performance was assessed as an average grade four months later. The results indicated gender differences in the perception of teacher and peers support, achievement goals and maths performance. The effects of goal orientations, teacher and peers support on achievement were moderated by gender. Furthermore, the interaction between classroom environment and performance goals on maths grades varied with gender. In the boys' sample, performance-avoidance goals interacted with teacher support, while in the girls' sample, performance-approach goals interacted with peers support in predicting maths grades. The educational implications of these gender differences are discussed. (Contains 2 figures and 2 tables.)