Today, fast fashion is experiencing rapid growth, which is increasingly pushing ethical shopping into the background. Even for consumers who have a strong awareness of sustainability, it is becoming increasingly difficult to translate their ethical principles into their shopping behavior due to the immense offer of fast fashion products. The aim of this study is to deepen the understanding of consumer exposure to fast fashion by synthesizing existing analytical methods with data on sustainability practices of fast fashion companies. We apply an online survey including items assigned to predefined factors, calculate sustainability performance of selected fast fashion companies and incorporate information into survey results. Finally, we group items per factor using cluster analysis and investigate strengths and directions of the relationships between factors and estimated clusters using descriptive analysis. The results indicate that respondents’ shopping patterns along with respondents’ opinions on the sustainability of selected fast fashion companies, has a discernible effect on their shopping behavior. A gap between consumers’ attitude and behavior could be observed, however, the results also show tendencies in the desired direction, as consumers with a strong attitude towards sustainability have the largest share among consumers with strong sustainable shopping behavior. It can also be observed, that female respondents have a much more pronounced sustainable attitude, but that male respondents pay more attention to sustainability when buying fast fashion. Generation Y exhibits a stronger environmental attitude towards shopping as well as a more pronounced sustainable shopping behavior than Generation Z. A difference in shopping behavior between consumers from urban and non-urban areas could not be determined. This study is a next step towards understanding consumer exposure to fast fashion consumption and potential barriers that influence the gap between shopping attitudes and behavior by linking relevant attitudinal and behavioral information on the consumer side with the sustainability practices of fast fashion companies using sampling and unsupervised analytical methods.