Although recent studies have found contingent self-esteem (CSE) to be negatively related to individuals’ well-being, research concerning its implications for motivation and engagement is scarce. In two studies, we investigated the relation between CSE, motivation, and engagement in achievement-related situations. A first cross-sectional study among second year high school students (N = 641; 54.1% female) confirmed the hypothesized motivational ambiguity associated with academic CSE. Beyond the contribution of academic self-esteem, academic CSE was positively related to behavioral and emotional engagement, but also to emotional disaffection and test anxiety. These associations could partially be explained by motivational quality, as CSE was also positively related to both autonomous and controlled types of motivation. In a second experimental study among university students (N = 72; 70.8% female), who participated in a tangram puzzle task under varying feedback circumstances, global CSE related to more tension, while predicting less behavioral task perseverance. These effects were not moderated by the type of feedback provided (i.e., positive vs. negative). Theoretical and practical implications of these results are discussed.