<p><strong>The escalating consumption of the new middle class, a large and rapidly growing consumer group in emerging markets, is a significant sustainability concern. This changing consumption differs from shifts that occurred previously in developed markets because the changes occur alongside the increasing global awareness of sustainability and the widespread negative impacts of climate change. New middle class consumers engage in some current consumption behaviours that have positive sustainability implications. However, status and lifestyle changes provide additional motivations and resources for consumers’ increased consumption, which drives the proliferation of less environmentally-friendly practices within the group. This study explores how these consumers experience sustainable consumption and navigate their behaviours during this transitional period.</strong></p><p>Previous literature often examines sustainable consumption either through individual psychological theoretical perspectives (linking components such as attitudes or beliefs to intentions and behaviours) or sociological lenses emphasising social elements such as culture. However, the persistence of the attitude-behaviour gap indicates that there are underexplored factors shaping sustainable consumption. This study uses social cognitive theory, which considers the reciprocal interaction of personal, environmental, and behavioural factors, to investigate the multiple, complex factors shaping consumers’ experiences of sustainable consumption and their behaviours in this transitional period. Adopting a hermeneutic phenomenological approach, this study analyses the wish lists, mobile diaries, and semi-structured interviews of eighteen urban new middle class consumers in Sri Lanka. The findings illustrate that these consumers participate in both sustainable and non-sustainable consumption behaviours with varying levels of conscious consideration for sustainability implications. By applying a social cognitive lens, this study illuminates the multiple, interacting factors that shape how these consumers experience sustainable consumption. Three groups of behaviours illustrate the consumers’ motivations: principled, self-gratifying, and controlled, each of which is shaped by differing factors. Through these findings, this study provides a conceptual model that proposes how changes in consumers’ present and proposed future behaviours will have important sustainability implications. This study offers direction for creating interventions in emerging markets that discourage or modify damaging behaviours, preserve behaviours that have positive sustainability implications, and facilitate consumers’ future sustainable consumption experiences.</p>