The purpose of this study is to define what data could be used to describe consumers’ actual behaviour when it comes to consumption of sustainable fashion. The perspective is both in terms of finding variables that describe the actual behaviour of sustainable consumption, and to create an appropriate measuring tool that can be used to measure those behaviours. This study has a qualitative research strategy with an inductive approach. The topic was examined by an extensive literature review in the fields connected to the topic. From the literature and the problem raised by the Swedish Consumer Agency, a questionnaire emerged. The questionnaire was also revised into a second version based on the feedback gathered during the focus group session. A questionnaire is suitable to get the consumer perspective, as well as cover all three stages of the consumption cycle and measuring over time. Additionally, this paper focuses on the environmental aspect of sustainability, but the importance of the social and economical aspects are acknowledged. The conclusions drawn in this paper were that it is important to measure the sustainable consumption behaviours of fashion consumers throughout the whole consumption span. When talking about consumption it is a common misconception to focus only on the purchase stage, when it really refers to the purchase, usages and end of use stage as a whole. The variables that were detected were presented in form of a questionnaire. The value of this paper is grounded in the developed questionnaire, which aims are to measure sustainable fashion consumption from a consumer perspective. This is interesting for the Swedish Consumer Agency, who requested a measuring tool, but it may also be of interest for other fashion companies to measure their consumer’s behaviour to detect a demand for sustainable products.