Design fiction (DF) is gaining ground as an approach that helps designers to explore possible futures. As a method founded upon critical attitudes and creative thinking, DF may be challenging for design students. In this study, we explore how design students use DF during creative design activities. Students engaged in an individual digital brainstorm and an in-depth, semi-structured interview about their experiences with the brainstorm based on DF. The results show that DF can be challenging for students who do not have a clear appreciation of what is technologically feasible for a particular time frame in the future and do not yet have the breadth of knowledge to argue about broader topics that DF is particularly attuned to into the discussion as, for example, economics and societal norms. This study contributes insights into how DF impacts the students’ design thinking, as well as difficulties they had regarding their individual thinking process.