AIMS: The aim of this study was to explore the experiences, values and preferences of people living with relapsing multiple sclerosis (PLwRMS) focusing on their treatments and what drives their treatment preferences. METHODS: In-depth, semi-structured, qualitative telephone interviews were conducted using a purposive sampling approach with 72 PLwRMS and 12 health care professionals (HCPs, MS specialist neurologists and nurses) from the United Kingdom, United States, Australia and Canada. Concept elicitation questioning was used to elicit PLwRMS' attitudes, beliefs and preferences towards features of disease-modifying treatments. Interviews with HCPs were conducted to inform on HCPs' experiences of treating PLwRMS. Responses were audio recorded and transcribed verbatim and then subjected to thematic analysis. RESULTS: Participants discussed numerous concepts that were important to them when making treatment decisions. Levels of importance participants placed on each concept, as well as reasons underpinning importance, varied substantially. The concepts with the greatest variability in terms of how much PLwRMS found them to be important in their decision-making process were mode of administration, speed of treatment effect, impact on reproduction and parenthood, impact on work and social life, patient engagement in decision making, and cost of treatment to the participant. Findings also demonstrated high variability in what participants described as their ideal treatment and the most important features a treatment should have. HCP findings provided clinical context for the treatment decision-making process and supported patient findings. CONCLUSIONS: Building upon previous stated preference research, this study highlighted the importance of qualitative research in understanding what drives patient preferences. Characterized by the heterogeneity of the RMS patient experience, findings indicate the nature of treatment decisions in RMS to be highly individualized, and the subjective relative importance placed on different treatment factors by PLwRMS to vary. Such qualitative patient preference evidence could offer valuable and supplementary insights, alongside quantitative data, to inform decision making related to RMS treatment.