Background. Current and potential future health-care users (i.e., the public) are important stakeholders in the transition towards environmentally sustainable healthcare. However, it remains unclear whether, according to the public, there is room for sustainable innovations in materials for plastic medical devices (PMD). This multi-method study explores preferences regarding conventional or bio-based PMD, and psychological mechanisms underlying these preferences.Methods. We administered two surveys among Dutch adults from a research panel. Results from the first survey (i.e., open-text survey on attitude elements; NStudy1 = 66) served as input for the second survey (i.e., Likert-scale survey on beliefs, emotions, perceived control, social norms, trust, related to current and bio-based PMD, and health and age; NStudy2 = 1001; Mage = 47.35; 54.4% female). The second survey was completed by 501 participants who, in the last two years, received care in which PMD were used, and 500 participants who did not. Psychological networks were estimated with data from the second study using the EBICglasso method.Findings. Participants preferred bio-based over conventional PMD, and this applied regardless of whether devices are used inside or outside of the body. Results showed emotions play an important role, with emotions regarding bio-based PMD being strongly related to preference. Furthermore, comparing recent and potential future users of PMD revealed differences in preference but comparable relations between preference and other psychological variables.Interpretation. This study shows that users’ perspectives should not be seen as potential barriers, but as additional motivation for transitioning towards sustainable healthcare. Finally, careful implementation is recommended.