Using a mixed-methods approach, this study addressed two related research questions. First, is there a discrepancy between consumers’ sustainable values and sustainable behaviour? While separate studies suggest that this disconnect exists, it has not been empirically validated within the same individuals in a single study. Second, if this discrepancy exists, what are the barriers to sustainable fashion consumption? It was found that, on average, subjective sustainable values were higher than objective sustainable behaviour. A one-sample t-test revealed that this difference was significantly different from zero, with a 99.9% margin of certainty. To identify the barriers that might explain why sustainable values do not appear to be translating into sustainable behaviour, interviews were conducted in participants’ wardrobes based on guided tour and personal inventory frameworks. Style, social repercussions, and wardrobe maintenance and disposal behaviour were the most frequently reported barrier-related themes. Results are discussed in light of promoting sustainable fashion consumption.