The purpose of this research was to gain an understanding of the knowledge that teachers in New Zealand primary school classrooms have in regard to phonemic awareness, their understanding of its importance as a factor in learning to read, and the methods they use to assess and teach it. International assessments continue to highlight an unacceptably large gap in reading achievement between good and poor readers in New Zealand primary schools (Mullis, Martin, Foy, & Drucker, 2012; Tunmer, Chapman, Greaney, Prochnow, & Arrow, 2013a). Up to 20% of children in New Zealand primary school classrooms are struggling to learn to read (Education and Science Committee, 2001, 2008; Education Review Office, 2005). Research shows that explicit instruction in phonemic awareness will help children struggling with reading to learn to read (Ehri et al., 2001; Hatcher, Hulme, & Snowling, 2004; Nicholson, 2003; Pressley, 2006; Ryder, Tunmer, & Greaney, 2008; Strattman & Hodson, 2005; Torgesen et al., 2001). Teachers’ knowledge of phonemic awareness becomes important in the context of providing this explicit instruction. An online survey was used to assess 68 in-service teachers’ knowledge of phonemic awareness. Four semi-structured interviews were also conducted which allowed the survey findings to be investigated further in four local contexts to add depth to the researcher’s understanding. Results revealed that participants struggled to define phonemic awareness, and did not understand the differences between phonemic awareness, phonological awareness, and phonics. Participants found some tasks more difficult than others, in particular phoneme counting and phoneme identity. There were also discrepancies between the participants’ perceived knowledge and their actual knowledge. Participants tended to overestimate their actual knowledge, perceiving themselves as more knowledgeable with regard to phonemic awareness than they actually were. Phonemic awareness did not appear to be regularly assessed nor explicitly taught in most of the participants’ classrooms. The findings suggest that the teachers who participated in this study did not typically have the knowledge of phonemic awareness needed to be able to provide the explicit instruction in phonemic awareness children struggling to learn to read need in order to become successful readers.