The study tested the hypothesis that negative academic emotions moderate the relationship between self-efficacy and achievement. The moderating effect of four negative academic emotions (anger, anxiety, shame, and hopelessness) was investigated in 1345 university students of trigonometry, who answered the Academic Emotions Questionnaire-Math (Pekrun et al. Educational Psychology Review 18:315–341, 2005) and a self-efficacy scale (Pintrich et al. Journal of Educational Psychology 82:33–40, 1991). Results of the moderation analysis indicated the higher self-efficacy was related to higher grades among students who reported lower levels of negative academic emotions. Self-efficacy had minimal or no effect on grades among students who reported higher levels of negative academic emotions. The results are discussed in terms of how negative emotions may indicate negative appraisals of the value of the task and/or task outcomes, and thus weaken the positive links between cognitive and motivational variables and learning.