This study examined the relationship between language mindsets and emotions through the mediation of competitive and cooperative orientations and positive and negative beliefs about competition. The participants were 603 EFL learners (M for age = 17.29, SD = 0.960). They responded to self-report scales on their mindsets, anxiety and enjoyment, beliefs about competition, and cooperative and competitive orientations. The results showed that growth mindset significantly predicted enjoyment, positive beliefs about competition, and cooperative orientation, while fixed mindsets significantly predicted anxiety, negative beliefs about competition, and competitive orientation. The results also indicated that growth mindsets predicted enjoyment through the mediation of positive beliefs about competition and cooperative orientation, and fixed mindsets predicted anxiety through the mediation of negative beliefs and competitive orientation. The implications of the study for language teachers and researchers are presented.