Purpose: Driven by the need to deepen understanding of the mechanisms driving teacher collaboration for enhancing teacher learning and practices, this study aims to investigate the influence of collaborative organizational conditions, network intentionality and efficacy for leading curriculum learning on teachers' professional growth within the context of New Zealand's Communities of Learning-Kahui Ako (CoL) policy. Design/methodology/approach: The study employs survey design collecting perceptual data from teachers within two CoLs comprising 12 schools in New Zealand. Structural equation modeling is used to analyze the relationships between collaborative organizational conditions, teachers' network intentionality, leadership efficacy and teacher professional growth. Findings: The findings reveal that collaborative organizational conditions significantly impact teachers' professional growth such as their new learning and enhanced practices. Furthermore, teachers' network intentionality and efficacy for leading curriculum learning serve as mediators, amplifying the effects of collaborative organizational conditions on teacher professional growth. Specifically, teachers who are more confident in their leadership abilities and intentionally build professional relationships are better at using collaborative opportunities to address teaching challenges and bring innovation to their schools. Originality/value: This study contributes to the existing literature by examining the interplay between organizational conditions, internal motivational drive for collaboration, and teacher professional growth within the context of CoL policy in New Zealand. It sheds light on the mechanisms driving teacher professional growth and offers insights for enhancing teacher collaboration and professional learning experiences within CoL networks.