According to the big-fish-little-pond (BFLP) model, the self-concept is not only influenced in a positive way by one's own achievement, but also in a negative way by one's relative achievement in comparison with one's immediate peers. This study investigates whether the BFLP effect also holds for second language acquisition. A random sample of 9167 Dutch-speaking students from Grade 8 took a reading comprehension test in French followed by a short background questionnaire in which they were asked for their self-concept of reading French. Multilevel regressions of the latter on individual and group achievement confirmed the BFLP effect but did not confirm an interaction of the effect with gender, individual achievement or class size. Moreover, in line with the local dominance hypothesis, it was shown that the negative effect of the average performance of peers is stronger for classmates than for schoolmates.