BACKGROUND: Multiple sclerosis (MS), a demyelinating condition of the central nervous system with an unpredictable course, has a major impact on the lives of people with MS. Partners of people with MS may be significantly affected by the diagnosis, management and uncertainty around disease progression and may provide substantial support and care. Modification of lifestyle risk factors in conjunction with standard medical management has been associated with improved physical and mental quality of life. Adopting major lifestyle modification may have a multi-faceted impact on the person with MS and their partner. Experiences of partners of people with MS have been previously explored, but the experiences of partners of people with MS who adopt this strategy have not. As part of a larger study that aimed to explore partners' lived experiences of and attitudes towards MS and lifestyle modification, this study reports the active steps and significant changes partners undertook to assist the person with MS and, at times, to also modify their own lives. DESIGN: Within an interpretive framework, using Heidegger's phenomenological philosophy, a qualitative study of semi-structured interviews was conducted. PARTICIPANTS: Aged greater than 18 years and in a spousal relationship with a person with MS who had undertaken an intensive residential lifestyle educational intervention promoting healthy lifestyle. RESULTS: Themes identified were: adjusting to lifestyle modification, understanding motivations and practical aspects of adjustment; seeking knowledge and support, exploring the ways partners sought positive support for themselves and the person with MS and abandoned negative influences; and embracing well-being, commitment and change, describing the major changes that partners made to their lives professionally and personally. CONCLUSIONS: The experiences of these partners provide clinicians with insight into potential motivations and outcomes of lifestyle modification and suggest potentially positive aspects for those directly and indirectly affected by MS.