Despite the large amount of research attention to engagement as well as positive psychology in a general context, there have been few attempts to increase academic well-being by means of positive psychological interventions. This article tests the potential of positive psychological interventions to enhance study-related positive emotions and academic engagement, and to reduce study-related negative emotions among university students. We modified two existing positive interventions that are aimed at increasing general happiness for use in an academic context. These interventions focused on "thoughts of gratitude" and "acts of kindness," respectively. The present study consisted of two randomized controlled trials with experimental (thoughts of gratitude or acts of kindness) and control conditions in which participants were monitored on a daily basis during the one-week intervention, and additional pre-, post-, and follow-up assessments were carried out. Results revealed that the gratitude intervention had a significant positive effect on daily positive emotions only. The kindness intervention had a positive influence on both positive emotions and academic engagement, though not in the long run. The results showed no effects on negative emotions in either of the two interventions. Positive psychological interventions seem to foster positive emotions and academic engagement, but do not decrease negative emotions.