Card sorting is one widely used method to design website information architectures based on an understanding of their users’ mental models. This paper studies the effect of participants’ sense of direction on card sorting results. To this end, a two-phase study for an eshop was conducted. In the first phase, 40 participants rated their sense of direction on the standardized Santa Barbara Sense of Direction scale (SBSOD) and were then involved in an open card sort study. Then, we analyzed the card sort data following a median-split approach based on participants’ self-reported SBSOD score. This resulted in two proposed information architectures for the eshop: one from the SBSOD-low participants and one from the SBSOD-high participants. In the second phase, we first developed two prototypes for the eshop, one for each proposed information architecture. Next, 30 participants were involved in a within-subjects user testing study. Results showed that users interacting with the eshop produced by the SBSOD-high participants were significantly more effective, more efficient and rated the tasks as easier compared to users interacting with the eshop produced by the SBSOD-low participants. No significant difference was observed for users’ perceived usability.