The professional development of teachers working at mainstream public schools in Kazakhstan has been placed at the cornerstone of secondary schooling reforms in the country. The paper discusses teachers’ attitudes and perceptions of their leadership roles at Nazarbayev Intellectual Schools in the context of translating their best teaching practices to teachers from mainstream schools. Are teachers ready to accept those roles of leaders and agents of change? And what skills do they need to cope with those changes? The study is based on the findings drawn from the mixed methods research with the interviews of focus groups and surveys of around 1,000 teachers who have taken CPD courses at the Centre of (Teaching) Excellence, Nazarbayev Intellectual Schools. The analysis is based on the critique of internal and external factors influencing teachers’ leadership roles as they cope with the mainstream innovations at the secondary schooling system.