The high demand for the fashion industry currently results in the emergence of the fast fashion phenomenon, prompting consumers to spend more money on unnecessary clothing. This leads to excessive clothing production, which impacts pollution, waste, and emissions. The phenomenon of excessive fashion consumption and production can be mitigated by utilizing second-hand clothing products. Purchasing second-hand clothing products can be classified as part of mindful consumption behavior. The aim of this study is to examine the direct and indirect effects of Electronic Word of Mouth on mindful consumption behavior in the context of local second-hand clothing purchases. Additionally, this study also tests the mediating effects of consumer engagement and environmental attitudes. This research is quantitative in nature, employing data collection through questionnaires from local second-hand clothing consumers within the active workforce demographic (aged 18–59) in Indonesia, yielding 205 respondents. The data analysis technique used is structural equation modeling-partial least square (SEM-PLS). The research findings indicate a significant positive direct influence of Electronic Word of Mouth on environmental attitudes, consumer engagement, and mindful consumption behavior. Moreover, there is a notable positive direct influence between consumer engagement and mindful consumption behavior, while no significant influence is found in the relationship between environmental attitudes and mindful consumption behavior. Furthermore, the study confirms the mediating effect of consumer engagement between Electronic Word of Mouth and mindful consumption behavior but does not support a significant mediating effect of environmental attitudes on local second-hand clothing mindful consumption behavior.