Bandura's concept of self-efficacy has been the focus of numerous research studies related to teacher self-efficacy. Most studies have investigated Bandura's first three sources of self-efficacy beliefs: mastery experiences, vicarious experiences, and social persuasion--with much less emphasis placed on Bandura's fourth source, the role of emotions. Essentially, teacher self-efficacy research has centred upon classroom practice and teachers' perceptions of their ability to bring about desired outcomes in relation to student learning. Much less is known about how teacher self-efficacy is shaped by teachers' emotions and factors outside the immediate sphere of their daily practice. This research project examined the impact on the self-efficacy of 202 practising primary teachers of completing a degree qualification some years after gaining their initial teaching qualification. Rather than the teachers' emotions and sense of self-efficacy being shaped by their practice, mastery of a degree was an emotional experience that shaped the teachers' personal self-efficacy and ultimately their sense of professional self-efficacy.