Consumers' product-disposal behaviors impact the environment, businesses, society, and consumer well-being. This research explores if and how consumers' disposal behaviors are influenced by sentiments of nostalgia. Four experimental studies are conducted, two on student samples and two on general population, to test our hypotheses. Study 1 shows that compared with collective nostalgia, personal nostalgia elicits higher intention to keep and reuse products. In contrast, collective nostalgia elicits higher intention to donate and recycle products. Both personal nostalgia and collective nostalgia reduce intention to throw away. Study 2 further corroborates the negative impact of personal nostalgia and collective nostalgia on throw away intention. Study 3 finds that the positive effect of personal nostalgia on keep and reuse intention is mediated by self-continuity. Finally, study 4 demonstrates that collective efficacy mediates the positive effect of collective nostalgia on donate and recycle intention. This study has theoretical contributions and practical implications for scholars and policy makers. 1 | INTRODUCTION Nostalgia, longing for the past (Routledge, Wildschut, Sedikides, & Juhl, 2013), is a frequently experienced sentiment. Although the concept of nostalgia originated from research in psychology, it has recently been introduced into research domains of political science, sociology, and marketing where it was recognized as a basic theme for many promotion and advertising programs (Muehling & Pascal, 2012). In the field of consumer behavior, nostalgia has been studied in various contexts, including brand loyalty, brand meaning, consumption preference, selective memory, and emotion (Muehling, Sprott, & Sprott, 2004). While the relation between consumers' purchase of new products and nostalgia has been explored, research is lacking on consumers' disposal of products at the end-of-use and nostalgia. The current research addresses this void. Consumers' product-disposal behaviors have important impacts on the environment, society, enterprises, and consumers themselves (Sandes, Leandro, Boaventura, & da Silva Junior, 2019). Proper disposal of products is vitally important for reducing resource waste, improving resource utilization, prolonging product life cycle, and product replacement decisions. Consumers may dispose of products by keeping, reusing, throwing away, donating, or recycling (Cruz-Cárdenas & Arévalo-Chávez, 2018). These disposal options are not equally sustainable. Throwing away or keeping (hoarding) are generally considered not environmentally friendly (Bye &