Self- and co-regulation are central elements in skillful student-teacher learning. Studies have confirmed the interrelation between positive academic emotions and student engagement in self-regulated learning. There are also indicators of student-teachers experiencing co-regulative learning activities as highly significant. Yet, we know surprisingly little about the emotional landscape of the self- and co-regulation of learning among student-teachers. Hence, in this study, we explore the kinds of academic emotions that primary school student-teachers experience during self- and co-regulated learning. Altogether 19 Finnish primary school student-teachers were interviewed. The data were qualitatively content analyzed. The results showed that both self- and co-regulated learning experiences were emotionally activating. Student-teachers reported primarily positive emotions (80%) in self- and co-regulated learning. The results also showed that positive activating emotions, such as enthusiasm, were emphasized in all regulatory phases: goal setting and task analysis, strategy use and monitoring, and reflection. Our findings on the high frequency of various positive emotions embedded in self- and co-regulated learning confirmed that positive activating emotions are essential elements in student-teachers self- and co-regulated learning. The findings imply that self- and co-regulated learning can trigger a positive cycle in student-teacher learning in terms of both emotions and productive learning.