Energy system models are widely used to explore, analyse and plan energy futures and sustainable transitions. These models, often developed in high-income countries, have more recently been applied in low- and middle-Income countries (LMICs). As a result, the role that modelling plays in informing decisions in such contexts lacks adequate exploration. Drawing on 35 qualitative interviews with energy system modellers and policymakers, this research examines the experiences of developing and using energy system models that support decision-making in LMICs. It shows that many conventional modelling approaches do not account for the political economy influences and developmental challenges specific to LMICs, with implications on modelling processes and outcomes. The interviews highlighted the need to understand the roles played by diverse stakeholders in shaping modelling processes as well as their communication, interpretation and use of energy models. This indicates that, especially in modelling projects which bring in external modellers, a good understanding of the country context is essential in order to design appropriate model scenarios and interpret them in the wider relevant context for policymaking. Finally, more in-country capacity is needed to foster local ownership of modelling projects.