This paper focuses on twenty newly qualified teachers who were teaching science and/or related subjects such as biology, chemistry and physics. In response to a 10-part self-efficacy scale included in the graduating questionnaire and at three interviews they demonstrated changing confidence regarding their effectiveness as teachers as they experienced reality in the classroom. These self-efficacy scores were analysed across the group and for individuals. Overall, self-efficacy ratings across the 20 NQTs indicate steadily dropping levels of confidence across the first 18-month teaching period with the biggest difference between the questionnaire and the first interview conducted after 6 months of teaching (Test of Within-Subject Contrast F (1,19 ) = 27.46 p<.001). However, a number of the teachers indicated an increase in confidence across the first 18 months of teaching and a small number indicated considerable drops in confidence. The interview data from these teachers indicate that their specific teaching context and the nature of induction they received were particularly important in supporting their professional learning and their confidence in their role of science teacher. These findings are noteworthy given that one variable identified by Rots and Aelterman (2008) as a predictor for commitment to teaching is that of teacher efficacy.