ASSIST is a school-based, peer-led smoking prevention program found effective in a RCT trial to preventing uptake of smoking in the UK. Influential students ('peer supporters') are nominated by classmates (not teachers) and receive training (outside of school) to engage in peer led conversations about the harms and benefits of not smoking. The aim of the ASSIST Global trial is to establish the feasibility and acceptability of the ASSIST intervention in Indonesia and the Philippines which have some of the highest reported global rates of tobacco use for young people, particularly males. This continued rise in youth smoking prevalence contrasts with a broad trend in the reduction of smoking, particularly in higher income countries. Implementing high quality RCT intervention studies with standardised evaluation techniques to prevent tobacco uptake for young people are mostly restricted to developed nations. This 'implementation gap' presents an opportunity to explore the potential of ASSIST to be implemented in different country and cultural settings. This paper reports the experiences of young people (13-15yrs) who adopted the role of peer supporter. This role is core to the delivery of ASSIST. Focus groups were held with the peer supporters (N=167) as part of a wider process evaluation. The analysis of this 'big-qual' dataset was facilitated through the Framework Method. Key themes include 'negotiating the decision to adopt the role of peer supporter', 'Facilitators and barriers in having conversations' and the 'psychosocial impact of occupying the role of peer supporter: Future Health Ambassador'. Cultural contexts were different between the countries. The peer supporters in Indonesia were able to reflect on the impact of Ramadan and Eid al-Fitr on performing this role. The results provide evidence to inform future implementation of ASSIST at a larger scale and point to adaptations necessary to suit different school systems, socio-cultural and policy contexts.