Participatory action research (PAR) was used to investigate the effect of a purposeful and sustained professional learning community (PLC) on teacher professional development (PD) in a secondary school context. A self-contained focus group of teachers organised in a learning community generated iterative data. The focus group meetings served as professional development sessions and data was collected through audio recordings. Inductive and comparative data analysis made meaning of the participants perceptions and compared their individual positioning. The findings indicate that teachers need favourable conditions for shared knowledge generation and focus group dynamics play a pivotal role in professional learning communities. It is recommended that purposeful and sustained professional learning communities be formed within and across New Zealand secondary schools and PAR as pedagogy is used as a PLC strategy for positive teacher PD outcomes.