The incremental theory of intelligence has been identified as a strong predictor of students' learning motivation. Recent research has suggested various moderators of its effect. The present study sought to examine the moderating effects of self-enhancement and self-criticism on the relation between incremental intelligence beliefs and students' motivational engagement. Responses were collected from 440 junior secondary school students in Macau. The results showed that self-enhancement strengthened the effect of incremental beliefs on students' efforts after a perceived failure. Self-criticism strengthened the effect of incremental beliefs on efforts after a perceived success. The reasons for these findings are discussed and their pedagogical implications elucidated.