PurposeThis research focuses on the consumption behavior of young consumers by examining their ecological consciousness and several self-oriented and psychological variables (fashion-orientation, frugality and psychological ownership toward the environment) that may trigger their sustainable purchase behavior. The research used “Psychological Ownership Theory” to examine sustainable purchase behavior in the context of apparel consumption.Design/methodology/approachTo gather data, a multi-method approach is used, including a scenario-based choice experiment (n = 62) and a structured survey (n = 338) using an online self-administered questionnaire. Data analysis was done using SPSS AMOS version 25 and PROCESS SPSS macro.FindingsThe results of the two studies revealed the mediation effect of “psychological ownership toward the environment” between ecological consciousness and sustainable purchasing behavior. Furthermore, fashion-orientation was found to be a significant moderating variable influencing sustainable purchase behavior; however, the impact of frugality was insignificant.Originality/valueThis research is one of the first that examined the mediation impact of psychological ownership of the environment in sustainable purchasing behavior using multi-method. The research focuses on the ecological consciousness of young consumers that develop psychological ownership.